Hi here i have seen several posting here for similar subject
My hot water cylinder split a few weeks ago, thankfully it was only a drip, however i decided this would be a good time to upgrade the system, i have a mistral oil fired boiler and a open vented C/H system, there has never been any discrimination to select just hot water or C/H only and the water never got very hot, but since fitting new cylinder and Drayton control unit with 3 way valve and cylinder stat the whole central heating system is great, But then i discovered that the bathroom radiator was on the HWC curcuit, this wasn’t a concern just more work. So now i have put the bathroom radiator on the proper circuit, which has now created another problem which is:
• The pump speed is set to no.2 and all the radiators heat up fine
• Select hot water and heating still all good
• Select just hot water and the water gets hot but a small amount of water passes from the vent line into the expansion tank in the roof. Turn the pump speed down to No.1 and this then stops, however on pump speed setting No.1 , two of the radiators struggle to get hot as per the other radiators
Do i just need to put some sort of restriction valve in HWC circuit, if so any idea what type
My hot water cylinder split a few weeks ago, thankfully it was only a drip, however i decided this would be a good time to upgrade the system, i have a mistral oil fired boiler and a open vented C/H system, there has never been any discrimination to select just hot water or C/H only and the water never got very hot, but since fitting new cylinder and Drayton control unit with 3 way valve and cylinder stat the whole central heating system is great, But then i discovered that the bathroom radiator was on the HWC curcuit, this wasn’t a concern just more work. So now i have put the bathroom radiator on the proper circuit, which has now created another problem which is:
• The pump speed is set to no.2 and all the radiators heat up fine
• Select hot water and heating still all good
• Select just hot water and the water gets hot but a small amount of water passes from the vent line into the expansion tank in the roof. Turn the pump speed down to No.1 and this then stops, however on pump speed setting No.1 , two of the radiators struggle to get hot as per the other radiators
Do i just need to put some sort of restriction valve in HWC circuit, if so any idea what type