C
csk423
My heating system is a sealed system with gas fired greenstar i24 serving a hot water cylinder and rads via a 2no. 2 port valve arrangement.
The greenstar was fitted 3yrs+ ago and ever since I have had a bang noise when the heating is switched off (either via stat or by the timer) the previous system boiler did not have an integral pump but a pump located adjacanet to the 2 port valves(removed when the new boiler was fitted) this only happens when the hot water is off, when hot water is on and the 2 port valve is open there is no bang.
So my thoughts are that as the new boiler has an integral pump and over run, when the stat or timer turns the heating off the pump runs on and snaps the heating 2 port valve shut.
The hot water valve is a drayton za5 and the heating valve is the older now obselete version Acl drayton.
To stop the bang I simply manually drove open the hot water 2 port and left open (switching the hot water off on the timer) meaning the heating kept the cylinder hot when the heating was on. In the summer I switch the heating off and run just the hot water, no demand for heat only the odd occassion.
Now I have an issue in which the heating will not come on despite the timer being on and the stat calling for heat, I suspect the 2 port heating is not making the end switch to start the pump on the boiler. This is the older of the 2 valves. When I opne the hot water 2 port it starts to heat the rads and the cyilnder ie the pump kicks in.
I think Im going to have to get the older 2 port changed due to the end switch issue, will changing this for a za5 model also stop it slamming shut ?
Edit, I meant to add my suspicion is it requires a bypass also as the pump will be pushing against a shut valve.
Apologies for the mamoth first post ! Any thoughts and advice on the above would be good.
The greenstar was fitted 3yrs+ ago and ever since I have had a bang noise when the heating is switched off (either via stat or by the timer) the previous system boiler did not have an integral pump but a pump located adjacanet to the 2 port valves(removed when the new boiler was fitted) this only happens when the hot water is off, when hot water is on and the 2 port valve is open there is no bang.
So my thoughts are that as the new boiler has an integral pump and over run, when the stat or timer turns the heating off the pump runs on and snaps the heating 2 port valve shut.
The hot water valve is a drayton za5 and the heating valve is the older now obselete version Acl drayton.
To stop the bang I simply manually drove open the hot water 2 port and left open (switching the hot water off on the timer) meaning the heating kept the cylinder hot when the heating was on. In the summer I switch the heating off and run just the hot water, no demand for heat only the odd occassion.
Now I have an issue in which the heating will not come on despite the timer being on and the stat calling for heat, I suspect the 2 port heating is not making the end switch to start the pump on the boiler. This is the older of the 2 valves. When I opne the hot water 2 port it starts to heat the rads and the cyilnder ie the pump kicks in.
I think Im going to have to get the older 2 port changed due to the end switch issue, will changing this for a za5 model also stop it slamming shut ?
Edit, I meant to add my suspicion is it requires a bypass also as the pump will be pushing against a shut valve.
Apologies for the mamoth first post ! Any thoughts and advice on the above would be good.
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