FOR the average small house an independent boiler is the most convenient. It should be the correct size for the duty it has to perform. Heating system boilers need to be selected by a heating engineer, as there are so many variable factors to be considered. As to fuel, coke of proper size, as supplied for boilers, is very convenient, but more difficult than anthracite to keep alight continuously. By careful stoking last thing at night, and a knowledgeable manipulation of the dampers, however, this trouble can be avoided. Much fuel is wasted by haphazard stoking. During periods when little hot water is needed, keep a low fire. The bed of ashes on the bars will itself slow down the functioning at ‘off’ times. Half-an-hour before hot water in more quantity is required, clear the fire bars with the rake, let the fire draw up for a few minutes, and feed in more fuel. Every chimney and flue has its own characteristics, which must be learnt so that the best use can be made of the dampers.
When about to burn up kitchen refuse, wait until a good red fire exists in the boiler, and then put in the refuse, as dry as possible. Remember that bones and similar matter will calcine to an inconsumable body like a clinker, and clog the bars. Have the boiler chimney swept at least every summer; at regular intervals examine the point where the smoke pipe enters the brickwork, to make sure the exit of the pipe is not choked by soot which has fallen down and become heaped up there. Clinker left uncleared on the firebars will tend to burn away the latter, so always clear the bars every night or morning. Where a boiler fire is to be kept alight for days together, it should be let out at least once a week to permit a thorough cleaning out of the furnace.
If water does not get hot enough, there are several things to suspect. First, make sure that no tap on the hot-water pipe line is dripping continuously; even a slight drip will entail a constant waste of hot and an intake of cold water. Make sure, too, that the fire burns briskly and that the flue and chimney give a good draught. There may be a permanent defect in construction or fixing which prevents sufficient pull on the smoke pipe. In the case of an old house to which a boiler has been fitted in place of some other appliance, the flue may not be sealed, or may even communicate with the flue for a fireplace in another room. Much depends on the duty demanded of the boiler, which may be more than such a boiler can normally fulfil. A heating engineer can deal with this matter. Even such a defect as a smoke pipe badly fitted to the brick flue may cause continued inefficient working. But independent domestic boilers have a wide margin of power over and above that normally needed, and it is exceptional for them to fail to give satisfaction.
Lagging the Pipes
If the hot water is unsatisfactory in cold weather months a good deal can be done by lagging the pipes and the hot storage cistern. Special felt or other insulating material in coils can be bought to wrap spirally around the piping in exposed positions (such as in the roof space) to conserve the heat. The hot cistern may waste a lot of heat, and unless this is compensated for by the use in an airing cupboard, it is a dead loss. Even in an airing cupboard the gain is questionable, since few people need this service twenty-four hours a day and seven days a week. To lag the cistern, box in the front with thin wood; usually there is only a small space at the sides, between the cistern and the walls of the cupboard. Fill in dry sawdust all round; take it over the top of the cistern, and cover over the latter with boards, leaving openings where the piping emerges. Probably the pipes themselves will supply enough warmth for airing clothes.
Much of what has been said above applies to these also. In a combined system, the tendency may be on some days to rob the boiler for hot water and so get less warmth from the radiators. Lagging of piping which may give off heat where it is not needed, e.g. in the roof space, is an obvious precaution to take. But even in the roof space, if the house has a cold aspect, it may be well to use discretion in lagging, as the piping above may serve a good purpose by preventing a freeze-up.
When radiators are first brought into use after a stand-by period, the air release valve on each should be opened to allow accumulated air to escape. This may be necessary also at other times if air accumulates in a radiator, though this question is too complex for discussion here. If a heating system has been emptied by draining radiators, pipes and boiler, the air valves have to be opened temporarily when refilling the system, since the incoming water drives air before it, and vents must be provided. Generally, in times of frost, all radiators on a circuit should be kept in use to guard against freezing; isolation of any one or more at such times may cause them to freeze. The heat output from a radiator may be improved for all practical purposes by fixing a flat shelf above it on simple brackets. Metallic paint on radiators blocks a good deal of radiant heat emission, and should not be used.
Use only good fuel for a heating boiler. Kitchen refuse is best disposed of elsewhere. Heat is obtainable only from combustible substances, and it is futile to stuff the boiler furnace with wet vegetable matter which, so far from contributing heat, needs other fuel to enable it to burn at all. Further, the flues get choked and the dampers also. Boilers of all types, whether for hot water or for heating systems, need periodical cleaning. In some districts the pipes and waterways get furred-up with scale much sooner than in. other districts. Formerly, the only practical treatment was to take down the boiler and clean it by mechanical means; piping, too, had to be treated in this drastic manner. But today, there are descaling liquids and compositions which, put into the boiler, etc., will remove the scale. A heating engineer will advise on such matters.
Boilers should be emptied in the ‘off’ season, and sediment or other loose foreign matter drained out. There is a residuum which does not normally get into active circulation by the pipes; by coupling a hose to the drain-cock at the bottom of the boiler, this can be flushed out. The local hot-water fitter should be asked to do this job once a year. It is not generally advisable for the householder to interfere with taps or valves on the system or to shut off the hot water circulation.