A recent repair of a glowworm betacom in Dulwich showed clearly what the results can be of poor installation work. In a way, I could understand why a heating engineer would have been fed up with this job. For starters, that part of SE21 is next to impossible to find a parking space at all. This particular road was a red route for quite a distance from the flat, so at any time it was a bit of a walk to get tools and materials on site. As if that was not enough, it was a top floor flat with a very narrow staircase.
However, the new owner of the flat was now stuck with a Glowworm that did all sorts of things apart from glowing, let alone burning. The betacom is no more complicated than your average boiler, but it can be awkward to work on due to the way it is designed. Some of the specific challenges of Glowworm Betacoms are described in more detail on the page dedicated to them.
If there is plenty of space around it, it’s not so bad. This one had not. It did give me a good idea for the blog though; creating a list of things for house or flat buyers to watch out for. For those that recognise items here but already have bought the place, it is not too late. If it is still working more or less as expected, you now have time to find yourself a good local boiler repair specialist, and get him to give the boiler a full service and a complete system check over, once the winter is over.
What are the giveaways that the installer may have cut some corners that will later on lead to unpleasant surprises?
One of the easiest things to spot for anyone, including people that are absolutely not technical, is an undersized gaspipe. In all but the most rare cases, a combi boiler will need at least a 22 millimetre gas supply. By default, combination boilers will have 5 pipes. Two are for the hot and cold water, and those can be 15 mm. That leave the heating “in and out” and the gas in 22. So if you see 2 big pipes and 3 thin ones, it is suspect.
One step more difficult is the flue. On condensing boilers, the flue should go slightly up toward the outside. Standard efficiency boilers should have a flue where the outside end is just a tad lower than inside. At all times, the gap where the flue goes through the wall, should be sealed with mortar on the outside. If you lift the covering collar around the flue, and you can see daylight, it’s not done properly.
Another fairly easy way to tell whether or not it was all done to spec, is to be found in the radiators. When they are all fully on, they should all be equally hot.
The next easy one is air in radiators. If you need to bleed them a bit once a year, that is not the end of the world. If you find significant amounts of air coming out on a regular basis, there is something wrong.
The last one that is easily recognisable, is only for condensing boilers. You guessed it: the condensate outlet.
The condensate pipe should be made of the standard white overflow pipe indoors, and either the same but well insulated if it goes outside, or a larger size 32, or even better 40 millimetre. It should always go down, either vertically, or with a slight slope. The slope is called “fall” and should be a minimum of 4%, which is half an inch vertically for each inch horizontally.
Why was it so obvious that this particular Glowworm Betacom was not installed correctly? It had all of the above failures, which first lead to an intermittent fault, and finally completely stopped the boiler from working. I repaired it for the time being, and will go back when it is a bit warmer and make sure that the owner won’t have the same problems in coming winters. One more client in SE21 who will not freeze up next year.