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Hi,
I replaced a faulty zone valve on the hot water side of what I believe is a S-plan (cold water tank + expansion tank in loft), vented, indirect heating system at my mother's house. The valve, a Drayton ZA5, had seized but additionally the head's microswitch back lugs holding it position had broken off and the actuator leaver was no longer able to make contact with the microswitch. I decided not to replace the head as although I freed the valve it was still very stiff and caked inside in build-up. I installed a Honeywell 4043H observing the flow direction of the previously installed ZA5 (A -> B).
In addition to this repair, I bought a new programmer (ESI ES3247B) to replace the Landis & Staefa RWB9 programmer that had yellowed, broken backplate "hook" holes, cracked in other places and generally appeared unsafe. I wired the backplate according to the previous controller's configuration and one which was configured to switch on the HW whenever the CH was turned on (more on this later). So far, so good I thought.
Radiators refilled with Sentinel X800 and switching the power to the heating system back on I tried the hot water first and pleasingly the HW zone valve did what it was designed to do which is rotate its lever and hit the microswitch to call for heat. Boiler fired up and started heating water pipe both sides of pump and HW zone valve but hot water in cylinder did not heat up after 20 minutes of being on. Pump and water in pipe making usual noises but I assume there is no flow for some reason.
I have drawn a crude diagram (attached) of what I can see in the airing cupboard and made an assumption about what is connected inside the cylinder, but the latter I could be wrong about. The flow directions marked on the pump and zone valves are original, as in I have not changed them, but I am confused about how hot water flows to the radiators which by the way still work fine.
My questions are:
Is the CH zone valve on the cold return rather than the hot feed?
What cold be the reasons I am getting no hot water but CH water is piping hot?
Do I have a fully pumped or partially pumped system?
Should the programmer be configured to be Gravity Fed so HW and CH come on together or Pumped so HW and CH can be independently controlled? I read on another forum something about needing the HW Off wired to the backplate for a Pumped system but the original backplate had only the HW and CH call connections wired (see attached).
Thanks!
I replaced a faulty zone valve on the hot water side of what I believe is a S-plan (cold water tank + expansion tank in loft), vented, indirect heating system at my mother's house. The valve, a Drayton ZA5, had seized but additionally the head's microswitch back lugs holding it position had broken off and the actuator leaver was no longer able to make contact with the microswitch. I decided not to replace the head as although I freed the valve it was still very stiff and caked inside in build-up. I installed a Honeywell 4043H observing the flow direction of the previously installed ZA5 (A -> B).
In addition to this repair, I bought a new programmer (ESI ES3247B) to replace the Landis & Staefa RWB9 programmer that had yellowed, broken backplate "hook" holes, cracked in other places and generally appeared unsafe. I wired the backplate according to the previous controller's configuration and one which was configured to switch on the HW whenever the CH was turned on (more on this later). So far, so good I thought.
Radiators refilled with Sentinel X800 and switching the power to the heating system back on I tried the hot water first and pleasingly the HW zone valve did what it was designed to do which is rotate its lever and hit the microswitch to call for heat. Boiler fired up and started heating water pipe both sides of pump and HW zone valve but hot water in cylinder did not heat up after 20 minutes of being on. Pump and water in pipe making usual noises but I assume there is no flow for some reason.
I have drawn a crude diagram (attached) of what I can see in the airing cupboard and made an assumption about what is connected inside the cylinder, but the latter I could be wrong about. The flow directions marked on the pump and zone valves are original, as in I have not changed them, but I am confused about how hot water flows to the radiators which by the way still work fine.
My questions are:
Is the CH zone valve on the cold return rather than the hot feed?
What cold be the reasons I am getting no hot water but CH water is piping hot?
Do I have a fully pumped or partially pumped system?
Should the programmer be configured to be Gravity Fed so HW and CH come on together or Pumped so HW and CH can be independently controlled? I read on another forum something about needing the HW Off wired to the backplate for a Pumped system but the original backplate had only the HW and CH call connections wired (see attached).
Thanks!
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