HW Tank not dumping excess hot water generated by a stove

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Father Ted
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HW Tank not dumping excess hot water generated by a stove

Post by Father Ted » Mon Dec 10, 2018 1:20 pm

Hi, we have just installed a back boiler stove into our home and there is a problem whereby the excess hot water is not being dumped into the radiators unless the central heating is turned on in order to turn on the room thermostats and also the pump.

We have an oil burner to provide HW & CH. There is also a stove which has a back boiler to provide hot water.

My expectation was that excess hot water (above the temp specified by the thermostat on the tank) would be sent to the radiators (or at least to an always on radiator). However the hot water tank does not seem to be able to regulate it self (continuing to increase temp without duping) and only did so when the heating was activated. In this instance the pump is turned on and pumps the water around the zone(s) which have been turned on. I've checked and during this time the oil burner is not turned on - as it is not required due to sufficient heat in the tank.

The room thermostats only operate (illuminating to show a heat demand) when the zone is turned on for central heating.

The supposed always on radiator is beside the thermostat in the hallway (I assume so due to it not having any thermostats on the valves. I also suspect that the towel radiator in the bathroom is also always on. However, none of these get heated when only the stove is heating the HW tank. Should the pump be required for these to turn on or should these be on a parallel circuit with the stove? I've checked and both of these radiators are on - when the CH is activated both warm up.

Should the thermostats and pump be independent of the central heating or should there be a switch in the controls to allow them to be permanently powered, regardless of the state of the central heating controller, in order to handle the back boiler?

I need to discuss this with the plumber, but would like some feedback on what is possible or what is the normal approach with this type of setup prior to contacting him - although, this may in fact be an issue for the electrician to resolve.

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Re: HW Tank not dumping excess hot water generated by a stov

Post by getthewheelsinline » Mon Dec 10, 2018 10:35 pm

Best bet would be get the HETAS engineer back ASAP to discuss issues. [emoji106]
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