Wood Burning Stove Maintenance
Exterior: The normal finish for wood burning stoves is a matt or metallic heat resistant paint. Matt black paint is available in a can and can be applied with a paintbrush; but all the other paints are supplied only in aerosol spray cans. The paint should be applied to a clean, dry surface, and the stove should be cold. Two or three thin coats is better than one thick coat to prevent it from running; as it becomes touch-dry in only a few minutes, it does not take too long to do. Although dust and ash can be removed from day to day with a soft brush or damp cloth, many owners touch up at least the front and top of their stove once a year to keep it looking like new.
After painting, an acrid smell will be given off the next time the stove is fired up; this is quite normal and happens while the new paint is curing (hardening). Leave the window open and the door of the room shut, and wait until the fumes have disappeared.
Enamelled stove finishes should be cleaned with a damp cloth when cool. The enamelling may chip if subjected to a knock by, for instance, a log or kettle. Crazing of the enamel sometimes occurs, and there is unfortunately not much one can do about it -- if this would upset you, much better to buy a stove with a painted finish which can be re-sprayed and kept in 'as new' appearance.
Bright cooking surfaces may be rejuvenated by applying a little Zebracier or similar proprietary metal polish.
Glass doors: The glass fitted to modern stoves is likely to be in one piece and made of a ceramic material, whereas in older stoves narrow strips of borosilicate glass were used. The strips are quite fragile and easily broken with a knock or, for instance, when the door is closed against a misplaced log. The strips also tend to distort and finally break after a few years' use. Expect to replace them about every 3 years.
Ceramic panels are much tougher and have comparatively low coefficients of expansion; they are however more expensive to replace when they do break. Again it tends to be knocks rather than heat which does the damage.
Because of the fragile nature of glass and the obvious possibility of accidents, it is never covered by stove guarantees.
Be careful when replacing glass strips or panels not to overtighten retaining screws/clips. Old worn gasket material around the glass should be replaced at the same time. Other sealing gaskets (made today from ceramic fibre/fibreglass rope in various diameters, rather than asbestos as in the past) will need replacing about every four or five years. You will usually find them around the edges of the doors and the ashpan cover (if your stove has one.) Scrape out the remains of the old gasket and adhesive with an old screwdriver tip, and use either high temperature adhesive or a special high temperature silicone (we now stock a silicone cartridge which will stand 1200 degrees C) to glue in the new gaskets. It is best to allow about 24 hours for the adhesive to set cold before lighting the stove.
The Baffle Plate: The baffle plate, which is normally fitted immediately above the flames, and the firebricks (where fitted), are 'sacrificial' in the sense that part of their purpose is to bear the brunt of the flames and protect the stove body. In time both will need replacement. How long they last will depend on a number of factors, but mainly on how often the stove is used and especially on whether it has been 'over-fired' at any time.
The Grate: Important! If you have a 'multifuel' stove or cooker, you will have some sort of fixed or removable grate fitted. It is very important not to allow the ash level to build up under the grate such that it touches its underside, otherwise the metal will almost certainly overheat and the grate can then burn through in a matter of days or weeks.
The grate in a stove where the coal ash is always removed daily should last for years; however, because of the possibility of abuse, grates -- like glass -- are always specifically excluded from the manufacturers' guarantees.
Central heating systems: If your stove runs a central heating system, here are a few tips:
- Circulating pump: during the summer, if the central heating is not in use for several months, run the pump for about ten minutes once a fortnight to prevent it from seizing up. The pump does a lot of work over the years and is likely to be the first item in the system to need replacement. Noises in the pipework may well stem from a worn pump bearing indicating that all is not well. (Note: if you have inherited a wood-fired central heating system and it does not have some type of pipe-thermostat control device fitted, such as a 'Minimax' or 'Highglow' controller, then it should have one. Without such a controller, boiler surface corrosion is an almost certain probability.
- Radiators: bleed air from the radiators using a special radiator key (obtainable from any good hardware shop for a few pence) if you notice that some radiators are cold near the top and hot at the bottom. Make certain when bleeding the air out that the pump is not running, otherwise air may be drawn into the system.
- Expansion tank: once or twice a year visually check the expansion tank. Make sure that the ball valve is not stuck by moving it downwards and checking that water then flows into the tank. Apply a little light oil to the pivot if necessary. Ensure that the overflow pipe is not blocked by debris or loft insulation which may have fallen into the tank.
- Inhibitor: indirect systems should be topped up with a suitable inhibitor (e.g. Fernox MB1 in the UK). Check the strength of the solution every two or three years. It is there to slow down corrosion in the pipework and boiler, and also lubricates the pump and adds a measure of frost protection in cold weather.