UFH actuator has started to close way before the room temperature is reached!!!

[Amarka]

Hi. First time poster here. My UFH doesn't heat up like it used to. I've isolated the issue (I think). It seems that whenever there is a call for UFH heat, the boiler fires up (like it used to), the actuator hums and opens up, the pump on the UFH manifold starts to run and the various valves on the polyplumb manifold open up...hot water starts to circulate through the pipes. In the past, the UFH would run until the required temperature is reached and then the actuator would close and the boiler goes into its 1-5minute overun and then shut until the next call. BUT now, within a minute of the UFH call, the ufh actuator closes and the boiler recycles and the ufh call still remains ie thermostat temp hasn’t been reached. we are now in a situation where the UFH doesn't run for long enough to warm the room so the bolier cycles continues until I turn the UFH thermostat down basically turning the call off. Any advice would be greatly appreciated. Thanks and hope all is well

 

[Amarka]

Hi. First time poster here.

Sorry. When I mention 'actuator' I am referring to the polyplumb motorised valve NOT the actuators that are on the UFH manifold

 

[Gasmk1]

Possibly faulty motor have had this years ago valve would open but once motor was warm it would close (winding on motor broken but made connection when cold), you can open it manually and lock it open) but it needs to open to bring the pump on you need either a new head if available or full new valve

 

[Amarka]

Possibly faulty motor have had this years ago valve would open but once motor was warm it would close (winding on motor broken but made connection when cold), you can open it manually and lock it open) but it needs to open to bring the pump on you need either a new head if available or full new valve

Thanks gasmk1. The exact replacement seems difficult to get hold of. Would you know if there is an alternative head I could use? I want to avoid having to replace the whole valve. Here is a pic of the current metal head - no product codes so can’t do a search.

 

[Gasmk1]

looks similar to honeywelll or tower are there numbers on the end should be a model number

 

[Amarka]

I’ll check the Polypipe brochure for those codes. In the meantime, I’ve manually opened the valve and rooms with UFH are being heated. Great news for household and NYE. Thanks for the advice Gasmk1. I’ll let you know how I get on with that replacement valve. Happy New Year!!!

looks similar to honeywelll or tower are there numbers on the end should be a mode

 

[Amarka]

Afternoon all and HNY! I’ve done some research on those codes. The Polypipe website has the 2-port zone Valve inc. Head code: UFH2PORTZV and then sold separately, just the steel head code UFHZVACT. I could just order the head but I was wondering from your experience, could I order a different replacement head without the need to replace the valve pipe work? Also, the head is 5-wired, the 4 normal ones you get say with the Danfoss HPA2 but also includes earth. So if a better option was to replace the valve and head, I’d feel more comfortable if the replacement was also 5-wired. Any thoughts?

 

[Gasmk1]

the 5th wire is added but not always used you will find that the 5th on yours will be into a blank or just cut and not used

 

[Amarka]

the 5th wire is added but not always used you will find that the 5th on yours will be into a blank or just cut and not used

Thanks Gasmk1. I’ll have to trace that Earth and see where it ends. Unfortunately the valve is near the boiler in one room whilst the UFH manifold is in the garage ( don’t ask!) If the earth is blanked, then I guess I could replace the whole valve and motor - with a Honeywell, better known brands. Something for tomorrow. Thanks again Gasmk1 - one this is all sorted, you and I will have a virtual beer!

 

[Amarka]

Thanks Gasmk1. I’ll have to trace that Earth and see where it ends. Unfortunately the valve is near the boiler in one room whilst the UFH manifold is in the garage ( don’t ask!) If the earth is blanked, then I guess I could replace the whole valve and motor - with a Honeywell, better known brands. Something for tomorrow. Thanks again Gasmk1 - one this is all sorted, you and I will have a virtual beer!

Hi Gasmk1. The existing Polypipe motor uses all 5 wires so I plan on changing the valve to a Honeywell V4043H 2port which also uses 5 wires. The new motor comes with the valve so Ill check if the motor fits on the existing Polypipe valve or not. With a quick drain, should be easy enough to fit both parts and wire up. Thanks again.