I have a vented oil fired heating system fitted with Grundfos dual headed circulating pumps and Grundfos pump plan wiring centre. There are no motorized valves in the system. I have just fitted TRV's to all the radiators and am going to fit an ABV between the CH flow and CH return. Does this have to be put immediately after the pump or can it be put in farther from the pump? It would be much easier for me to fit it between the flow and return pipes feeding the rad in our spare bedroom .
Position for an automatic bypass valve
- Thread starter Bigjr
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Yes it can go further from the pump, but unless there'a a boiler overrun keeping that particular pump running, it may not do much good.
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If you have TRVs on all rads now then yes, the ABV is a good idea (overrun or not)
Doesnt need to be right after the pump, infact the further away the better, as long as theres no way of it being isolated under normal operation
Doesnt need to be right after the pump, infact the further away the better, as long as theres no way of it being isolated under normal operation
Justin, thanks for your reply.
CH pump is controlled by the times set by the programmer so the pump runs even when the boiler is is not due to temperature cut out. I want to fit an ABV to prevent the pump getting damaged
CH pump is controlled by the times set by the programmer so the pump runs even when the boiler is is not due to temperature cut out. I want to fit an ABV to prevent the pump getting damaged
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But does the boiler need a bypass/overrun arrangement?
Certainly if you have no permanently open rad valves then the pump has nowhere to pump to, but that's going to damage the boiler (if it needs to lose heat) before the pump.
If the programmer turns the pump and boiler off together then the boiler still sits there cooking, like a car brewing itself up in a motorway service car park.
Certainly if you have no permanently open rad valves then the pump has nowhere to pump to, but that's going to damage the boiler (if it needs to lose heat) before the pump.
If the programmer turns the pump and boiler off together then the boiler still sits there cooking, like a car brewing itself up in a motorway service car park.
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You need the ABV regardless as you have now fitted TRV's To All Rads. When the house is warm on occassion it will be entirely possible for all the valves to clows at the same time, so the boiler will be firing with no where to pump heat to. The ABV will correct this and also protect the pump.
Whether the boiler needs the pumps to have an OverRun after heat demand will be entirely down to the instructions for the boiler. It was very common for older cast Iron units to not need such an overrun.
Whether the boiler needs the pumps to have an OverRun after heat demand will be entirely down to the instructions for the boiler. It was very common for older cast Iron units to not need such an overrun.
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