Pump Running, but no demand

[Harry Bloomfield]

I’ll have a look tonight. The actuator is definitely driving the valve open/shut as I can hear the change in water flow

Possibly the microswitch then, not confirming it has closed. You need to trace where that signal for the boiler to run, is coming from.

 

[Gasguru]

Often the spring lugs break off and the valve doesn't fully return leaving the microswitch closed despite the motor being unpowered.

 

[Bon]

Thanks. I have one of those ready to go if the above attempt fails. Wanted to avoid a drain down if possible as it’s a gravity-fed heating system

 

[Bon]

Possibly the microswitch then, not confirming it has closed. You need to trace where that signal for the boiler to run, is coming from.

I did that last night. Traced the orange wire from the hot water actuator to the switched live wire block in the wiring centre. That then feeds a cable that runs to the garage and connects to the boiler live cable. In the garage there’s another wiring centre which has (bizarrely) a second core from the above cupboard-to-garage wire that connects to the pump live wire.

If I remove the switched live wire from the hot water valve everything works fine (except the hot water obviously)

 

[gas112]

Thanks. I have one of those ready to go if the above attempt fails. Wanted to avoid a drain down if possible as it’s a gravity-fed heating system

if your valve is less than 30 year old then the actuator should come off without any need to drain down

 

[Harry Bloomfield]

I did that last night. Traced the orange wire from the hot water actuator to the switched live wire block in the wiring centre. That then feeds a cable that runs to the garage and connects to the boiler live cable. In the garage there’s another wiring centre which has (bizarrely) a second core from the above cupboard-to-garage wire that connects to the pump live wire.

If I remove the switched live wire from the hot water valve everything works fine (except the hot water obviously)

Micros switch then, or as suggested above, the spring not returning it.

 

[Rodders53]

I have swapped the microswitch on those heads (or BG branded equivalent) a few times for the late in-Laws. Often seems to be a sticky grease off the drive that clogs up the actuator of the switch so some cleanup / isopropyl on a cotton bud can sort temporarily.

The Burgess microswitch is as cheap as chips but requires some dismantling and a soldering iron.

Not had the return spring fail described above - but that'd allow water to flow through the valve and not give the water hammer described? In-laws pumped over into the header tank when stuck on.

 

[Bon]

Thanks guys. I wired in the new actuator from the new valve I’ve got this evening (without the valve body fitted to the pipe).

Valve opened on both time clock and stat demand and turned the pump on. On time-clock off and stat-off, valve closed and pump switched off perfectly.

I can’t get the old actuator head off to look at it for love nor money so going to let it cool overnight, bite the bullet and swap the whole thing out tomorrow.

Thanks for all your help - much appreciated

 

[Gasguru]

 

[Harry Bloomfield]

Thanks guys. I wired in the new actuator from the new valve I’ve got this evening (without the valve body fitted to the pipe).

Valve opened on both time clock and stat demand and turned the pump on. On time-clock off and stat-off, valve closed and pump switched off perfectly.

I can’t get the old actuator head off to look at it for love nor money so going to let it cool overnight, bite the bullet and swap the whole thing out tomorrow.

Thanks for all your help - much appreciated

If you close, both sides of the radiator valves, upstairs, your drain down to just below the valve, will only need to drain the water in the pipe work.

 

[Bon]

If you close, both sides of the radiator valves, upstairs, your drain down to just below the valve, will only need to drain the water in the pipe work.

Thanks. Going to plug the F&E tank, isolate all but the tallest upstairs rad (towel rail) then open a drain cock on a downstairs rad. I can top the inhibitor up through the top of the towel rail when done then