Hi Guys
Myself and my Dad have had a search around here and found a few relevant posts but I am hoping a heating engineer may be able to confirm our issue.
Brother recently moved into a house with a vented and fully pumped CH and HW system complete with 3 way valve.
On initial inspection it was found that selecting the heating on the control panel also switched on the hot water. This was then found to be due to the fact that he control panel was set to a gravity fed hot water system which this system is definitely not.
Having changed the control point to a pumped system (allowing independent selection of CH & HW) and also the cylinder stat, which was faulty and stuck in "call" mode, the hot water then worked fine, with the 3WV diverting water ONLY to the cylinder when the cylinder stat called for heat.
However, on selecting the CH on at the control panel with the HW not selected, the boiler and pump do not fire up, although we think that the 3WV does open as the motor is heard.
If the HW and the CH are selected on the control panel, with the room stat calling for heat and the cylinder stat NOT calling for heat, the boiler fires, the pump runs and the 3WV diverts to rads only. If the cylinder stat then calls for heat also, the 3WV diverts to both rads and cylinder. Likewise, when the room stat stops calling for heat, the 3WV diverts back to the cylinder only (providing HW is calling for heat).
It seems the CH will work if the HW is selected, whether HW is calling for heat or not, but will not work without the HW selected.
We have identified that this must be a 3WV microswitch issue or a wiring issue. We have mapped out a wiring diagram which I will be looking at tonight but initial inspection looks OK. Would you therefore conclude this to be a 3WV micro switch issue? Is it possible to be a microswitch issue in this case?
Further testing may be required!
Thanks for any help anyone can give!!
Myself and my Dad have had a search around here and found a few relevant posts but I am hoping a heating engineer may be able to confirm our issue.
Brother recently moved into a house with a vented and fully pumped CH and HW system complete with 3 way valve.
On initial inspection it was found that selecting the heating on the control panel also switched on the hot water. This was then found to be due to the fact that he control panel was set to a gravity fed hot water system which this system is definitely not.
Having changed the control point to a pumped system (allowing independent selection of CH & HW) and also the cylinder stat, which was faulty and stuck in "call" mode, the hot water then worked fine, with the 3WV diverting water ONLY to the cylinder when the cylinder stat called for heat.
However, on selecting the CH on at the control panel with the HW not selected, the boiler and pump do not fire up, although we think that the 3WV does open as the motor is heard.
If the HW and the CH are selected on the control panel, with the room stat calling for heat and the cylinder stat NOT calling for heat, the boiler fires, the pump runs and the 3WV diverts to rads only. If the cylinder stat then calls for heat also, the 3WV diverts to both rads and cylinder. Likewise, when the room stat stops calling for heat, the 3WV diverts back to the cylinder only (providing HW is calling for heat).
It seems the CH will work if the HW is selected, whether HW is calling for heat or not, but will not work without the HW selected.
We have identified that this must be a 3WV microswitch issue or a wiring issue. We have mapped out a wiring diagram which I will be looking at tonight but initial inspection looks OK. Would you therefore conclude this to be a 3WV micro switch issue? Is it possible to be a microswitch issue in this case?
Further testing may be required!
Thanks for any help anyone can give!!