Saturday 17 January, 2015 by Uncle Spike
This is the second of a very strange couple of posts to share some of the less salubrious aspects of rural life; which on balance is never as simple and clean as life in a developed area I have to say. All good fun though 🙂
In part one, it was the heat exchanger in the top section of the furnace that was cleaned. When I say ‘heat exchanger’, I am talking about the place where the heat generated from the burner itself passes through 15 tubes around which some 140 litres (37 US gals) of water are heated up. The resulting hot water is then pumped through to the heat exchanger tubes inside the hot water tank (for the shower etc), and then on to the panel radiators around the house (depending on which valves I open/close)… before returning as cooler water to be reheated and circulated all over again.
So anyway, after cleaning the air blades and tubes, and then removing soot from the upper chamber (pushing it all through so that it drops to the burn chamber below), the inner door is put back in place, and the heavy outer door to the top chamber is closed. The lower door to the burner chamber itself is then opened…
This much larger ‘open’ chamber needs a fair amount of scraping too, with the ‘ceiling’, walls and back all requiring some attention with the scraper rod, and in places, the wire brush. A lovely messy job 🙂
The large cast iron centre burn unit is where all the action happens. The coal is auger fed from the hopper into this unit, and when lit, multi-jet fan outlets blast air into the fire to ramp up the core temperature, and thereby efficiently burn the coal fuel in order to pass more heat up into the heat exchanger unit.
A strange ‘heavy’ ash falls through the air holes into a collection chamber, which has to be cleaned out too. When I say heavy, I can only relate it to the weight of human ashes one receives back from a crematorium; as in it wouldn’t blow away in a light wind like normal coal ash.
Usually it takes as much as two full loads to empty the entire burn chamber of waste product, even then, it’s hard enough to lift a full pan over the fence to the waste area. The waste removed contains the soot from both the upper and lower chambers, the waste coal, and everything else scraped away.
Then it’s time to squeeze around to the back of the furnace. I don’t have to clean the metal flue of the chimney itself – that’s a once-a-year job after the season is over each springtime. But I do have to remove the soot that collects in the air chamber which sits directly below the opening for the flue dampener.
That old ice-cream tub can be filled up ten times over !
The final task in this monthly cleaning marathon involves checking and servicing the mechanics of the furnace. The air fan has to be checked, and the filters kept clear of dirt, or stuff blown in from outside such as leaves, hay or feathers.
The chunky electric motor and the gearing mechanism that drives the auger is then checked and re-greased as required, as without that, the system will cease to work, and I’ll be in the dog-house 🙂
Now that the furnace is all cleaned and serviced, it has to be refuelled and prepared for lighting...