The foremost thing in any stove maintenance programme is to ensure the chimney is swept on a regular basis. Have a look at our article on: Chimney cleaning for woodburning and multifuel stoves.
Make sure the woodburning or multifuel stove has been fitted properly. You may also want to read our article on: Fitting of woodburning and multifuel stoves.
The second procedure in the stove maintenance programme is to check the stove for poor seals which causes excess air to be drawn into the lit fire chamber resulting in lack of control of the burning fuel, poor combustion and under certain conditions gas leaks from the stove. This is best carried out at the start or end of each heating season or if at anytime the stove burning becomes more difficult to control.
Before you start please make a quick sketch of the stove.
Simply close all the air intakes of the lit stove, put on a pair of heat protecting gloves and take a cigarette lighter or a gas hob lighter. Slowly move the lit cigarette lighter or gas hob lighter around the stove door where it seals against the doorframe. Best to ensure that there are no major drafts in the room at the time of doing this. If the lighter flame is drawn towards the door seals at any point you immediately know that excess air is being drawn into the combustion chamber at this point. Note the whereabouts of any leaks on the sketch and carry on around the glass where it meets the door to ensure there are no leaks between the glass and the glass rope seal. Some cast-iron multifuel and woodburning stoves are bolted together by a system using iron rods that pass through the stove corners from the top of the stove plate through the insides of the stove to the underside of the base plate where they are bolted…Another method used is with interconnected lugs and bolts inside the woodburning or multifuel stove. All the cast-iron plates 6 in all, the top, base, front, back and two sides normally have grooves so they interconnect well before being bolted together. The grooves are normally lined with fire cement at the time of manufacture to ensure a good airtight seal. Run the lighter slowly along the joints where all the plates meet both vertically and horizontally right around the stove, again noting any point where the flame is being drawn to-wards the stove. Job done, you now know whether or not your stove is still working as it was designed to do or if it has developed a few leaks due to wear and tear.
The next stage in the stove maintenance programme is to sort out any of the leaks that may have been found as soon as possible. Let the woodburning or multifuel stove go out and do not light again until the leaks have been fixed. Poor sealing here under certain conditions can cause poisonous undetectable gases such as carbon monoxide to enter the leaving quarters if poor combustion is taking place in the stove. This is a special concern if smokeless or fossil fuels are being burnt in a multifuel stove. I like to leave the rest of the stove maintenance to the end of the heating season for reasons that will be explained later.
Once the fire in the woodburning or multifuel stove is out and the stove has cooled down, any leaks in the interconnected stove plates can be quickly sorted. In the past I have heard of people breaking their stove apart, re-fire cementing the plate joints and rebuilding the stove. I personally feel this is too much hard work and the same results can be achieved using a much more simplified method. The lid or top plate on most cast iron wood burning or multifuel stoves have a lip, which overhangs the stove body. Check your diagram from earlier to see if you have detected any leaks in this area. Run your finger under the lip where the lower plates are joined to the top plate. You may find excess fire cement that has squeezed out from the joints and hardened at the time of manufacture. I normally remove the excess with a strong flat-headed screwdriver and a mallet, tapping the excess off along the joints. I use a rubber mallet so if I miss I don’t damage the stove in any way .Now smooth off with wire wool. Nowadays you can purchase black high temperature silicon, which is great for this job. Fire cement eventually cracks with heat and falls out so I avoid using it whenever I can. Put the silicon tube into the silicon gun and cut a small angle slot at the top of the tube. Squeeze the silicone into the areas that are leaking or do all the plates, as it will last for a very long time and reduce future maintenance. Any excess you create can be easily wiped off with a small damp sponge.
The next stage of stove maintenance is to sort out the leaks where the door meets the doorframe of the woodburning or multifuel stove. Again in a cast-iron stove you will find that most doors close into a groove in the cast-iron doorframe. Sometimes the door catches or hinges are adjustable, if so consult your user manual instructions for the adjustment methods. I have found this more on traditional steel stoves, which makes more sense, as they don’t have the groove arrangement. The simple remedy is to replace the acrylic / fibreglass rope door seal. The glass rope seal can also be changed at this time if you have found leaks there, but make sure firstly that the glass is over the seal on all four sides as sometimes the glass moves a fraction due to the fact that on some stoves the glass is only held in place with lightly tightened metal clips. Most doors just lift off as they are hinged with removable pins so the rope can be replaced with the door lying flat. Remove the offending rope seals and take them to your local plumbers merchant, stove merchant or hardware store where the diameter can be checked and you can buy replacement lengths off a roll. Plumber’s merchants normally carry all sizes of this type of rope. There is a special rope seal glue you can also buy to complete the job, but yet again when I have been stuck I have used the high temperature silicon with no problems at all afterwards.
Clean out the door groove with a small screwdriver and smooth off with wire wool.
Just over half fill the groove with the adhesive you have purchased and apply the new rope being careful not to stretch it in any way. Tuck the two raw ends where they meet into each other and you are finished.
Now I have a reason why I always do the full stove maintenance at the end of the heating season (with the exception of checking and fixing leaks in the stove casing joints or doors) Spare parts at the start and during the heating season if needed are not always readily available because of demand. This then is a good time to always check the inside of the burning chamber of your woodburning or multifuel stove for wear and tear. As you wont be using the stove for some months to come it gives you plenty of time to order the parts if needed. Worst case scenario you might need a new baffle plate, firebricks or cast-iron linings, a grate or ashpan.
The baffle plate is the piece of cast iron, steel plate or scamalux board , which straddles the stove inside the upper part of the fire chamber. It is an important piece of kit as it deflects heat back into the chamber, thereby protecting the lid from excessive temperatures and aids in the secondary burning system of the woodburning stove. The baffle plate also creates a ventura effect for the draw of the stove. Replace this if warped badly or at least order a new one if it looks like it won’t last another heating season. The plate can be a bolt free fitting, but is normally held in place with bolts through a couple of lugs on which the plate rests. Some manufacturers use different methods to keep the baffle plate in place so consult your user manual for this if it is not obvious.
Cast-iron woodburning or multifuel stoves normally have internal cast-iron or firebrick linings to protect the outer cast iron and reflect heat back into the fire chamber. I simply replace these with scamalux board. This is a high temperature insulation board, which you can easily cut into the firebrick sizes, or cast lining plate sizes inside your stove .It is normally 20 to 25 mm thick. In the case of cast-iron liners fitted inside the stove, check with your supplier that it is OK to replace with scamalux board so you don’t infringe any warranty you may still have on the stove.
Check the pyroceramic stove glass for crazing, as the high temperatures seem to cause this over time. Measure the size and make sure you replace like for like. Your stove supplier can provide this if you have the stove make and model number. Carefully refit trying not to over tighten the screws. The glass may be great for high temperatures but it is susceptible to uneven stresses and knocks. The glass is sometimes held in place with small clips, so if this is the case put a small piece of flat fire tape seal, also available for stoves, between each clip and the glass surface. This does help reduce cracking from a slightly over tightened clip.
The final part of the stove maintenance programme although not essential is to buy some high temperature stove paint (assuming your stove is not enamelled.) This is available in sprays and brush on so you can have your stove looking like new again while it is sitting there over the summer months poised for action. While using the spray, which I prefer, mask off the glass and brass or chrome handles and hinges and surrounding areas. Best to use a mask and open a window if you are in a confined space as it has a very strong smell. The paint normally dries at normal room temperature in a very short space of time. Never ever use on a warm stove. Re light the stove on a cool summer evening just to re-test your joints. Don’t be over concerned if a little air seems to be drawn through the upper control vent when closed. Remember a woodburning or multifuel stove fire chamber requires a little oxygen to stay lit. Total starvation of air and the fire will go out.
I have a story if your not too tired reading all this information on stove maintenance.
Sometime ago an elderly gentleman and his wife who had purchased several multifuel stoves from my shop for holiday homes told me that they were having a big problem with a smoking stove in their home that they had purchased some years ago from another supplier. They were advised that there chimney was at fault and it needed lined with a flexible liner. This seemed strange to me as the stove had been working perfectly for years, the chimney cleaned regularly, had a good clay liner and no cracks or leaks had developed. They took the advice and although costly had the chimney lined, as it was a good idea for the long-term life of the chimney and stove efficiency. However the multifuel stove still did not draw any better and smoke still filled the room when it was lit. They then decided that the stove must just be too old and needed replaced. I suggested that if they didn’t mind I would like a look at the stove, as I was intrigued by this story.
When I visited the home the fault was quickly apparent. The cast-iron lid on the top of the stove was a little loose. On examination inside the multifuel stove I could see that one of the bolted lugs holding the lid down had broken. This meant that air was being drawn into the stove via the top plate rushing up the chimney and upsetting the whole combustion process within the fire chamber of the multifuel stove. I tried a simple solution to resolve this rather than take the stove apart or replace it. I simply used high temperature black silicon under the lid to seal it again and advised the couple to leave it 24 hours before re-lighting. The result was 100% successful and shortly afterwards a new lug was welded inside the stove. That was almost 5 years ago now, and the multifuel stove is still performing well and staying in overnight as and when desired. Thankfully this elderly couples’ serious stove leak problem showed up immediately on the bolted stove lug breaking. Imagine the possible consequences if it had been a combination of small leaks due to lack of stove maintenance over the years and they had have been burning fuel with the odourless carbon monoxide gas being emitted into the room due to the stove combustion gradually deteriorating.
A wood burning or multifuel stove is a very efficient and safe way to heat a home but always remember that chimney and stove maintenance are very important factors to maintain a safe as well as a warm home.