Installing A Wood Burning Stove Or Boiler Stove – A Do It Yourself Guide

My Wood Burning Boiler

wood-burning-stoveThis stove provides me with full central heating and hot water. The entire system is gravity fed, needs no pump and is not connected to the grid. There could be a total power out, and I would still be warm in winter.

Self Sufficiency: The First Step

When it comes to becoming more self sufficient, there are variations on a theme short of hacking out a clearing in the woods and building a homestead. Most of us can’t do that; but many of us can achieve some of the key elements of self sufficiency in town or suburban dwellings. A good place to start is with wood stoves, or even better: A do it yourself wood burning boiler stove that will give you hot water and central heating. In addition you can generate your own electricity, grow a certain amount of your own food. This is bedrock stuff when it comes to survival: having a roof over your head, having enough to eat and being warm in winter. These basics cost a lot of money; and are about to cost a whole lot more. So whatever you can do to reduce those costs has to be due a little thought. If you can pull it off; the savings are considerable and could well make the difference between hanging on to what you’ve got; and not.

Free Fuel

Pallets are a useful fuel resource. They are carbon neutral, chemical free, heat treated, renewable timber. You have to be prepared to collect them and cut them up; so “free” is relative.

Installing a Wood Burning Stove: My Criteria

I live in a three bedroom semi detached house in a rural area; and my journey to free energy and self sufficiency starts with a multi fuel boiler stove. A multi fuel stove is one that can burn smokeless coal products or wood. The criteria I set out were: that it had to provide more than enough domestic hot water, and central heating for a shirtsleeve environment in winter , it had to be independent of mains electricity, ie, no pump and no electrically operated valves, I had to have as much free wood as possible; preferably all of it, and I had to be able to install the stove myself. Before I could do any of that though I had to modify my fireplace.

Wood Burning Stove D.I.Y Installation

Installing the stove yourself will maximise the savings on installation costs and free fuel, and you will probably get your money back within a season. But you do not have to do it yourself. You could pay for the installation and then reimburse yourself with tariff free energy over a longer period. Alternatively you could have those parts installed that you are not confident with and do the rest of the work yourself. I considered this option when I had reservations over the building work involved in opening up the fireplace.

In the end I tackled the whole job because none of the builders could be bothered to do the job the way I wanted it done. They preferred to just remove the fireplace, block up the hole, lay slabs in front for a hearth, dump the stove on it, smash a hole through my chimney breast and my beautiful clay liner, stuff the flue through it and connect to a flexible flue liner. In and out in a day fifteen hundred smackers thank you very much.

If you do decide to do the whole thing yourself, be advised; this is no small job. I had to take it one step at a time. I learned on the job, trawled the net, had builders in to give me quotes and picked their brains. Some builders were helpful with advice and allayed some of my fears. They were also interested in the idea of mains free energy; but doubted I could make it work.

Wood Burning Stoves: Building Regulations

The first thing I did though before starting work was to register an application with the local planning department and had building control check out my fireplace. With their approval, mitigated somewhat by their doubts over my stamina; I started work. I still do not know if the they were running a book down at the Town Hall on when I would call in the professionals.

You can download the regulations for the UK here:

This installation guide is based upon my own experience; and is not to be taken as an instruction for all circumstances. All fireplaces will differ, most will be similar. Do your research, look up fireplace construction on the net. Read forum posts on the subject. Download regulations pertaining to solid fuel boilers and stoves. Make yourself an expert on your own chimney. The regulations have a long winded way of saying: don’t set fire to your house, and don’t gas yourself with carbon monoxide. Download your stove manufactures installation instructions.
The fireplace with the builders opening cleared out up to the bottom of the clay liner. An old back boiler has been removed, and the new lintel awaits installation.

Removing The Fireplace


This was the easy part. Most fire surrounds are lightly fixed with small brackets and just need prizing off the wall. The hearth was pre-cast concrete bedded on a weak cement mix and yielded to a crow bar. If the fire surround is concrete too, it will be heavy, so CAUTION is required; do not allow it to fall over when it comes free of the wall or it will destroy all in its path, including your legs. Lower it gently flat to the floor, and then up end it so the heavy bit is at the bottom; it will then be relatively stable. You can then get it on rollers ( short lengths of broom stick, or stout metal pipe) and take it outside.

Removal of the fire surround will reveal the full dimensions of the builders opening, which is the term used to describe the hole in the chimney into which the fire place and its’ accoutrements are fitted. It will be larger than was visible through the surround, but will have been tailored to fit. In my case the width was reduced by the width of a brick on either side, and up to a height level with the top of the surround where a throat forming lintel was fitted. As the name suggests this lintels primary function is to direct air flow. It would have supported the few bricks above that are used to close off the upper part of the builders opening while their cement was drying, but is not otherwise load bearing. Mine fell apart as I removed it. I had expected to find a more meaningful lintel, but realised later that such was not necessary for this part of the chimney.

With Acro’s and Strong boys preventing any ‘sag’ of the brickwork above, the new lintel can be put in place.
This shows the packing hammered in above and below the lintel. This prevents the weight of the lintel compressing the wet cement below and maintains direct contact with the bricks above.

The exact placing of the new lintel will depend on the height of your stove and the thickness of your hearth. Make sure you give yourself enough height. If I were doing this again I would fit my lintel two brick courses higher. I ended up struggling for a couple of inches when connecting the flue pipe to the clay liner.

To fit the lintel you need to remove bricks to the length of your lintel. Remove enough bricks to give yourself room to manoeuvre at either end. My lintel was five feet. To be on the safe side I supported the upper brickwork with two size ‘0’ acro’s with strong boys. To remove the bricks I used a reciprocating saw with a masonry blade to cut through the mortar; but it was still tedious. I had better results with a masonry drill bit in my Black and Decker which I used like a router. If you can get yourself an Allsaw so much the better.

With the bricks removed the lintel can go in. Be aware it is not enough just to cement the lintel in. It needs to be packed with incompressible material at each end where it will bear on the piers beneath, and also along the top at intervals. This prevents any possible movement of the brickwork above when the cement dries out and shrinks a little. Builders usually pack in wedges of broken slate and tap it into the wet cement with a small hammer. Underneath of course you only need to cement in for the width of your pier. The minimum width of pier for a lintel of this length is six inches. Check with building control; or ask your builders merchant.

The lower rim of the clay liner before any modification. Note: the rim is not horizontal. The liner rises at around 7 degrees off the vertical for five feet, where it connects to the main chimney and a square 8″ clay liner. The lower rim of the liner after modification to align it with top of the lintel. Note: the rubble infill to the side.

Other Supporting Measures

It is not just the front wall of the fire breast that may need support. Much depends on how your system is put together and how you intend to connect your stove flue to your chimney. None of this is difficult. Whatever your configuration there will be a way to deal with it. On line stove suppliers will be only too willing to advise, particularly the one your are buying your stove from.

In my case I wanted to use a chimney sump adaptor as the connecting device between the stove pipe and the liner. They are supposed to be ‘glued’ to the bottom of a circular clay liner. Engineers however feel they should be bolted, but you cannot bolt to clay, so an interface was needed. I chose to use a quarter inch thick steel plate of about fifteen inches square with a centrally disposed eight inch hole. I could use the plate as a lintel under the clay liner, and I could drill and tap four bolt holes and bolt the adaptor to it, and achieve a tar proof seal with high temperature ceramic mastic.

The steel plate was rested on the front lintel and let into the rear brickwork by about two and a half inches. In order to fit the plate I had to cut off a segment from the bottom of the clay liner to render it horizontal and align it with the top of the lintel. It is perfectly OK to cut the clay liner if you need to. I used a diamond wheel from a small angle grinder modified to fit a regular power drill which I could insert up into the liner. By this means I achieved a horizontal cut and the liner made good and square contact with the steel lintel plate.

I also felt I needed to support the loose brick rubble that was used to infill the void on either side of the flue, which would be left hanging when all below the lintel was removed. This rubble has a function. Together with the odd trowel full of cement it provides frictional support to the clay liner.

I achieved the objective with four short pieces of one inch angle iron, two on each side of the flue cemented into the rear wall and resting on the lintel, and into which I fitted sections of paving slab from a defunct part of my patio. With the slab in place I inserted pieces of brick into the gap above to make sure there was no room for anything to drop from above.

Fireplace Enlargement

I intended to install my stove in the fireplace, which meant a do it yourself fireplace enlargement. These stoves however can be installed in dwellings that have no fireplace, on an outside wall with a stainless steel flue running up the outside of the house. The benefits of free fuel remain and I would imagine the installation would be somewhat less arduous than my experience, though having done it once it will be easier next time.

Cutting the piers

With the lintels in place and all supported; the piers can be cut. Be sure to measure accurately. I measured with my stove as the reference point rather than the minimum width of pier I could get away with, that gave me a nine inch pier. I marked my cut with chalk and fixed a piece of batten onto the wall to make sure the cuts were vertical. It is crucial to cut vertically and square to the wall.

It is impractical to make these cuts with anything other than a 12″ angle grinder fitted with a diamond cutter; but with a nine or twelve inch disc they are heavy and fearsome beasts so once again, CAUTION, the tool hire shop will advise. You may wish to use: ear defenders, mask and goggles, steel cap boots. This will not be a long job. It will take longer to get to and from the hire shop; but the dust will be all pervading and you will be glad when it’s over.

Since writing this page I have come across a new cutting device called the Allsaw. The Allsaw is a much more civilised device than the angle grinder and you may care to look it up at the hire shop, on Google or the auction sites.
Tidy up the enlarged opening

With the fireplace opened up the space can be prepared to receive the stove, and at this point consideration must be given to the plumbing. Two pairs of one inch copper pipes will need to be routed to the boiler, probably through the side walls. In my case I had removed a back boiler so half the plumbing was already in place, I just had to take two more pipes through the opposite side wall to TEE in to the central heating system on the first floor. You need to punch through the walls a good six inches above their respective union on the back of the boiler; this will provide a good rise for the hot flow pipe and a good fall for the cold return. Have in mind also that boilers have pipe unions on the rear side. In order to connect the plumbing the stove needs to stand off the rear wall by about five inches. This will influence the alignment of the chimney liner to the stove pipe. I had a five inch offset, which I felt I could accommodate with flexible stove pipe or modified elbows.

With this preparation complete the hearth can be constructed, the new opening can be decorated and those places difficult to access when the stove is fitted can be tidied up. I covered the bottom of the paving slabs and angle iron holding up the brick rubble above with white fire board, which can be cut with a craft knife and looks OK undecorated. I used quarry tiles on the hearth and fitted a grill over the underfloor air duct. I was now ready to roll in the stove.

Chimney liners

This is as good a place as any for a word about flexible chimney liners. All the engineers you speak to will recommend installing a flexible flue liner. They will have cautionary tales of chimney fires, acid attack on the brick mortar, tar and creosote running down the chimney and seeping through the joints on your stove pipe, etc. If you have an old brick chimney they may have a point; up to a point. If however like me you have a clay liner I would think more carefully about it. I had my chimney inspected and leak tested by the professionals and my chimney was declared an ‘A’ class chimney, which means ‘perfect’. So I decided not to install a flexible liner A: because I didn’t need one, B: because I could not fit one myself,and C: they are expensive.

Furthermore there are fittings specifically designed to connect to clay liners without a flexible liner, like the sump adaptor that I have chosen. There is also a method of connecting the stove flue via what is known as a register plate. This is a steel plate fitted just inside the chimney to seal it off from the room below. Your six inch stove pipe connects underneath and dispenses smoke into the chimney above, be it unlined brick or clay. A soot door is situated to one side for sweeping the chimney. So even unlined brick is not uncommon.

The secret of avoiding chimney fires is to sweep your chimney more often. Some recommend twice a year some three times a year. Certainly you will have to sweep your chimney no less with a flexible liner than you will without one because you cannot afford a chimney fire in either case.

Buy your own chimney sweeping brushes and do it yourself. Then you can do it six times a year and you will never have to worry about it.

Other precautions are 1: use stove protector. This is a granulated compound containing copper which combines with the soot, tar and creosote to form clinker. Add it to the fuel when lighting the fire every four or five days and when you sweep it comes down as a shower of soot and small cinders. I have never had liquid tar running down my chimney.

And 2: DO NOT burn unseasoned timber. Water vapour combines with smoke to make tar and creosote and promotes acid attack on the motor between your bricks.

Choosing a Wood Burning Stove

You need to have some idea of the stove you want before you start work on any alterations so the work can be carried out to easily accommodate the stove; the job has to be possible. So there are calculations to be made from the outset. Having done that it is vital to choose a stove of the right capacity. Too small and you will have to blast the heck out it to keep warm; too large and you will not be able to share the same room. I chose a multi fuel boiler stove that could run up to ten radiators plus the hot water via an indirect hot water cylinder of around 36 Imperial gallons, 43 US gallons. The output of the stove into the lounge is, 18000 BTUs, this enabled me to remove the two largest radiators currently served by the propane gas boiler, so the stove only had to serve eight radiators, thus bringing the required output well within the capacity of the stove. I did not calculate the entire dwelling as all rooms already had radiators appropriate to their size.

The Stove in The Fireplace: Connecting up The Flue

These stoves weigh in at around 300lb to 500lb, so just getting it into the house will be a test of your ingenuity. Most useful tools will be: rollers, levers and bad language. I didn’t find an expletive that would levitate the stove; but I tried.

Having got it into the lounge I rolled it on to the hearth with heavy duty appliance rollers, which I had to modify to position the wheels to fit directly under the feet of the stove. I then used a 4” x 4” wooden fence post as a lever to take it off the rollers to inch it in to its’ final position. From this point I calculated the positions of the pipework and how to connect the stove flue to the sump adaptor; and thence to the lintel plate. I first drilled and tapped four holes in the lintel plate and bolted the sump adaptor to it and sealed the joint with high temperature ceramic sealant specially made for the job. This sealant was to prevent tar deposits leaking out rather than gas and smoke.

The flue and the plumbing need to connected such, that work can be carried out on either without having to move the stove and disturb the other. I was restricted for space with the flue, and had to modify two 45 degree elbows. I fitted them to the collar on the stove before sliding the collar into place and bolting it from underneath.

The joints on the flue fittings providing they are properly fitted do not have to be sealed, but they do have be assembled with the female part at the bottom. I know this sounds counter intuitive and the issue is debated. However you cannot defy the laws of physics. The gas pressure inside the stove is always lower than the air outside, so air is drawn into the flue through any gaps rather than gas and smoke leaking out; if however the joint is assembled upside down, tar and creosote will leak out under gravity. Some though, still seal the joints with fire cement to be on the safe side. If you have larger gaps than you feel safe with you can use fire rope and fire cement. Building control in the UK now stipulate that a carbon monoxide alarm be fitted in the fire room.

Protecting Copper Pipe From Chemical Attack

When passing copper pipe through a brick wall, make sure it is passed through a sleeve so it does not come into direct contact with cement. Over time cement will attack the copper and result in pin hole leaks. The pipe can also be coated with oil based paint or bitumen.

Connecting Up The Plumbing

It’s worth saying at this point; that solid fuel boilers have to be what they call ‘fully vented’. That is they have to be open to atmosphere, so if it has to blow off steam; it can. This is achieved with a header tank, sometimes called an expansion tank, which is usually situated in the roof space. The tank allows the water in the system to expand and contract with temperature without allowing air into the system, and at the same time keeps the system charged with water. This header tank must be dedicated to the boiler. This is achieved by means of a half inch feed pipe which connects to the cold return to the boiler, adjacent to the hot water cylinder. The vent is by a three quarter inch vent pipe from the hot flow side, which goes up into the roof space and loops over the header tank to vent down into it. The tank itself is kept topped up from the mains through a ball valve. A pressure relief valve is also required for added safety. This is fitted to the rising hot pipe from the boiler. The hot pipe is referred to as the ‘flow’ and the cold as the ‘return’, and they must be both one inch, or 28mm pipes because the hot water tank is gravity fed from the boiler. The pipe unions on the boiler are standard one inch BSP fittings. A separate header tank is required for the hot water cylinder.

All dwellings will require different pipe layouts. There are many examples on the net and stove web sites. Your local plumbers merchant will be interested in your project and will be helpful with tips on how to proceed. He may even give you a trade discount, knowing that you will shop around for the best deal and that you will be spending a few smackeroos on fittings.

If you are using soldered joints and do not know how to solder there is information on the net and related hubs. You may wish to practice inexpensively on 1/2″ joints and offcuts; it’s not difficult. Just make sure your joints are clean, very clean, use flux and a good solder and don’t set fire to your curtains. See this video for a demonstration.

My stove was connecting to existing pipework from my old back boiler, so all that side of it was in place and functional. If you are working in the UK, all your pipe unions and new piping will be metric, but if you are in a pre metric house, which most houses are in the UK, all the original plumbing will be in inches. Where compression fittings are required the two sizes are compatible, but both Imperial and metric olives are available for all compression unions anyway. The boiler has standard 1” BSP female unions. The 28mm compression fitting required to connect will screw directly onto the boiler at one end, and at the other will accommodate both 1” and 28mm pipe. Solder joints however will not fit. Metric unions will have to be enlarged, or the pipe will have to be reduced. This is practical for 1/2” pipe but virtually imposable for 1” pipe. It is better to cut back the inch pipe to a convenient point and fit a 28mm to 1” adaptor that will fit over the inch pipe and go metric from there. If your in the United States, where sanity still prevails there will be no problems of compatibility.

On the central heating side, I was removing my old gas boiler and replacing it with the solid fuel boiler. All I had to do was isolate the old boiler from its’ associated pipework and connect up. The existing pipe work serving the radiators was 3/4” inch, or 22mm which ran to within a few feet of each radiator where it connected to 1/2″ pipe for the remaining few feet. I intended to run the new solid fuel system without a pump so had to run 1” pipe from the boiler to the TEE in point with the 3/4″ pipe under the floor boards on the landing.

Plumbers told me it wouldn’t work without a pump. It would be OK upstairs but downstairs would be a problem. The only two downstairs radiators that I needed to work were the hall and the kitchen. Both these radiators were situated on the other side of the wall from the boiler, one on each side and adjacent to the two pairs of pipes, so I was able to TEE in directly I raised both a foot or so up the wall to raise their tops well above the top of boiler; they both get sizzling hot.

The upstairs radiators all work equally well. What surprised me was that the two radiators in the lounge, that are now surplus to requirements, but which I have not yet plumbed out, also work, but only if all the others are turned off. Considering that both are fed from upstairs, and the flow and return have between them have at least thirty feet of half inch pipe along which to travel, I am amazed they work at all.

If I were designing a system from scratch I would use large bore pipe throughout and there would be no problem running pump free, and therefore mains free. I have made a system designed to run with a pump; run without one, using mostly existing pipework. If one could tolerate 1” pipe throughout it would be guaranteed to work. Some find large bore pipe unsightly, but I think you would get over it when the power went down and the oil ran out.

Swarf Wand and nails

Pallets cut down to log sized spacers and 12″ or so planks. Stack the planks to make a rectangular log and they take longer to burn. You will accumulate a lot of nails in the grate.
Pallets cut down to log sized spacers and 12″ or so planks. Stack the planks to make a rectangular log and they take longer to burn. You will accumulate a lot of nails in the grate.
I usually take out the nails every three days or so. The swarf wand enables you de-nail while the ashes are still hot.

The Fuel: Free wood

Essentially this is what this post is all about. The stove is just the means to an end. I chose a multi fuel boiler stove to give me a plan B, but it was the free wood that I had my eye on, and a boiler stove enabled me to make the most of it.

Unless you have your own woodland; free wood, for the most part has to be scavenged. That is not as bad as it sounds. I source most of mine from industrial estates in the form of pallets. Most firms are glad to have you take them away, otherwise they have to pay for there disposal. You could view yourself as a service provider, or part of the green revolution, recycling waste wood and making it part of the nations carbon neutral fuel strategy. Most pallets I see have the sustainable woodland logo stamped on them, so you can burn them with a clear conscience so long as they are not painted.

It takes 3 or 4 minutes to cut up a pallet using a reciprocating saw with a log blade. The best I managed was 24 pallets in two hours. It would probably be quicker with a chain saw.

If you burn pallets you will accumulate a lot of nails in the grate. These can be easily removed on a daily basis with hand magnet or magnetic swarf wand.

Pallets are not the only source of free wood. Manufacturers have offcuts, as do timber yards. Other sources can be found on the net. All that is required is that you are prepared to do what it takes to avail yourself of this free resource.


The decor is somewhat spartan at this stage; and one may wish to conceal the plumbing. This however is not a fashion statement. It is a working stove in a working household and is a first step towards greater self sufficient mains free living.The decor is somewhat spartan at this stage; and one may wish to conceal the plumbing. This however is not a fashion statement. It is a working stove in a working household and is a first step towards greater self sufficient mains free living.

Whatever you burn on your stove make sure it’s legal; the information is out there. Adhere to manufactures installation instructions. Use Building control, they are not your enemy, get it properly signed off, it has implications for your house insurance.

When you have done all of that, your satisfaction and indeed gratification will be all the greater, and your unmitigated pleasure as you sit in front of your glowing fire with a beverage of your choice, will be further compounded by the three FREES!