Hello,
We’ve recently moved into a fairly old, fairly big detached house (i.e. fairly draughty, but not too bad by any means) with a fairly new well maintained Worcester combi boiler. We weren’t convinced the heating was working right and then got hit with a £610 energy bill for the first 6 months! Anyway, after some investigation we have found:
The Central Heating “seems” to work fine. The CH water flow temperature can be viewed directly in the display. When the CH kicks in, you can see the boiler water temperature rise and feel the radiators gradually heating up. CH water temperature is set to 70degC on the boiler which it gets to and maintains and all the radiators get nice and hot and heat the house. I don’t have any experience with the rate at which the water is heated - it does seem to take a while but not so much that I think there’s a problem.
The issue comes when there is then a demand for hot water. As with any combi, priority is given to hot water so CH switches off. Once hot water demand ends, there is a pre-set delay in the boiler before the CH kicks in again. However during this period of hot water demand and delay, the CH water seems to lose a lot of heat. When the CH kicks in again, the water temp will be around 5 - 10 degrees less than where it was, it will rise by a couple of degrees and then actually fall by around another 5 degrees before starting to heat up again towards the set point. This seems like a big waste of energy, but ok for a one off hot water demand. But when there are multiple hot water demands over a period of time as with normal domestic use the CH can’t keep up when it kicks back in. It loses too much heat during the hot water/delay phase and takes too long to get back up to temperature that the CH water temperature never gets hot enough to get the radiators anything over luke warm before the next hot water demand cycle causes the CH temperature to reduce even further. Therefore the rooms never heat up but all the while the...
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We’ve recently moved into a fairly old, fairly big detached house (i.e. fairly draughty, but not too bad by any means) with a fairly new well maintained Worcester combi boiler. We weren’t convinced the heating was working right and then got hit with a £610 energy bill for the first 6 months! Anyway, after some investigation we have found:
The Central Heating “seems” to work fine. The CH water flow temperature can be viewed directly in the display. When the CH kicks in, you can see the boiler water temperature rise and feel the radiators gradually heating up. CH water temperature is set to 70degC on the boiler which it gets to and maintains and all the radiators get nice and hot and heat the house. I don’t have any experience with the rate at which the water is heated - it does seem to take a while but not so much that I think there’s a problem.
The issue comes when there is then a demand for hot water. As with any combi, priority is given to hot water so CH switches off. Once hot water demand ends, there is a pre-set delay in the boiler before the CH kicks in again. However during this period of hot water demand and delay, the CH water seems to lose a lot of heat. When the CH kicks in again, the water temp will be around 5 - 10 degrees less than where it was, it will rise by a couple of degrees and then actually fall by around another 5 degrees before starting to heat up again towards the set point. This seems like a big waste of energy, but ok for a one off hot water demand. But when there are multiple hot water demands over a period of time as with normal domestic use the CH can’t keep up when it kicks back in. It loses too much heat during the hot water/delay phase and takes too long to get back up to temperature that the CH water temperature never gets hot enough to get the radiators anything over luke warm before the next hot water demand cycle causes the CH temperature to reduce even further. Therefore the rooms never heat up but all the while the...
Read more
Continue reading...
