Hot water cylinder losing heat
- Thread starter JonBodge
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I do remember one install where the vent pipe was too low, and it caused circulation into the header tank, have you checked the header tank is cold?
I use a C Plan with a poorly insulated 40 gallon cylinder and I know running central heating boiler every other day for ½ hour at a time in the summer, kept us with hot water at the taps, no shower from the DHW.
However when we installed solar panels, we started to use the immersion instead, it would turn off due to water at set temp, but next day if no excess sun, water cold, as it is only heating top of cylinder not the whole cylinder like the CH boiler did.
I used time, as no cylinder thermostat when using the central heating boiler to heat DHW, however with the Y Plan clearly there is a tank thermostat, so why is it switched off? The Y Plan motorised valve if no DHW is called for can be held fully over and can result in it getting quite warm. It is switched off DHW with a live supply not on, so not sure being only switched on for a short time is a good idea?
The hot coil can cool as well as heat the water in the tank, it should be arranged so thermo-syphon will not cause a flow through the pipe work when boiler is not running, the main advantage of the Y Plan is with a boiler with no cool down time, on switch off the boiler can cool by heating the DHW, with no power to the valve, it is as default on DHW, if the boiler is higher than the cylinder then the cylinder could heat the boiler. Not seen this with a boiler, but have seen it with electric heated towel rails where the towel rail heater was trying to heat other radiators in the home.
My last home we had a problem with upstairs radiators getting warm with thermo-syphon, even when pump turned off. We went over to using an instant gas boiler for DHW which cured the problem, not done to cure problem, done so we could turn airing cupboard into a bedroom, this was before the combi boiler came in, likely 35 years ago.
I use a C Plan with a poorly insulated 40 gallon cylinder and I know running central heating boiler every other day for ½ hour at a time in the summer, kept us with hot water at the taps, no shower from the DHW.
However when we installed solar panels, we started to use the immersion instead, it would turn off due to water at set temp, but next day if no excess sun, water cold, as it is only heating top of cylinder not the whole cylinder like the CH boiler did.
I used time, as no cylinder thermostat when using the central heating boiler to heat DHW, however with the Y Plan clearly there is a tank thermostat, so why is it switched off? The Y Plan motorised valve if no DHW is called for can be held fully over and can result in it getting quite warm. It is switched off DHW with a live supply not on, so not sure being only switched on for a short time is a good idea?
The hot coil can cool as well as heat the water in the tank, it should be arranged so thermo-syphon will not cause a flow through the pipe work when boiler is not running, the main advantage of the Y Plan is with a boiler with no cool down time, on switch off the boiler can cool by heating the DHW, with no power to the valve, it is as default on DHW, if the boiler is higher than the cylinder then the cylinder could heat the boiler. Not seen this with a boiler, but have seen it with electric heated towel rails where the towel rail heater was trying to heat other radiators in the home.
My last home we had a problem with upstairs radiators getting warm with thermo-syphon, even when pump turned off. We went over to using an instant gas boiler for DHW which cured the problem, not done to cure problem, done so we could turn airing cupboard into a bedroom, this was before the combi boiler came in, likely 35 years ago.
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Not sure if this will help but we have an similar unvented HW cylinder but we have put an additional old school insulation jacket over it as well as the foam that is on the HW cylinder.
At the bottom of the cylinder it looks like it looses 5 degC in 3.75 hrs
At the bottom of the cylinder it looks like it looses 5 degC in 3.75 hrs
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