Circulation pump permanently on

[rolyberkin]

Can anyone help, I have looked at a central heating pump for my brother in law (who is a plumber!? it is an HRM oil fired boiler, the problem is that the circulation pump is permanently on, there is underfloor heating with the system, the wiring is shocking and I will probably have to re wire everything but just looking at a quick fix prior to pulling it all out and starting again.

I tested everything out a few weeks back and changed the head on one of the two port valves which appeared to solve the problem, I then left and then it has started running permanently again?

Any ideas as I am a bit lost, is it likely to be some kind of pump over run issue?

Thanks

 

[HandySparks]

I think the best thing is to trace the pump supply wiring back to the various things it might be connected to (boiler, valves, etc.) and see which one is providing the unwanted feed.

 

[Midwest]

Can anyone help, I have looked at a central heating pump for my brother in law (who is a plumber!? it is an HRM oil fired boiler, the problem is that the circulation pump is permanently on, there is underfloor heating with the system, the wiring is shocking and I will probably have to re wire everything but just looking at a quick fix prior to pulling it all out and starting again.

I tested everything out a few weeks back and changed the head on one of the two port valves which appeared to solve the problem, I then left and then it has started running permanently again?

Any ideas as I am a bit lost, is it likely to be some kind of pump over run issue?

Thanks

Expect its probably the other head gone now.

 

[streamer]

I had a faulty valve head a while ago and changing it solved the problem for a short time. When the replacement stopped working I took it off and realised the valve itself had become very stiff which is probably what caused the first one to pack in. A bit of WD40 on the valve fixed it.

 

[rolyberkin]

I am convinced it is one of the valves however I wondered if the boiler has a pump run on thermostat or device, I wondered whether that was faulty and when it got up to temperature permanently on?

 

[Last plumber]

Is it just the pump that runs or is the Boiler on with it ?

Or does the Boiler work as it is expected ?

Is this a proper S PLAN ? ( I know there's more than one Two port MV but how many? and what on? )

If it's a correctly wired S plan then the supply to the pump will either come from the Orange ( normally ) wires off the two ports or from the Boiler (for the over run) as you mentioned.

If it's not wired correctly then as you know it could be anything ( cylinder stats, room stats, frost stats for example).

If I ever come across problems like this and it's not obvious, I always disconnect everything and start again. More often than not it is easier and quicker than trying to identify what someone else did wrong or trace/find a back feeds from something or find faults .

 

[rolyberkin]

Thanks, yes I think the whole thing is a crock of ---- and needs rewiring, I have never seen such a bodge and In think his woes started around the time he had an underfloor zone added on. I will go up there and do it for him, the problem is I am in Essex, he is in Lincolnshire, payment will no doubt be a curry and beer!

As I recall I think there are three two port valves, one for heating, one for hot water and one for an underfloor heating zone, cannot remember what controls he has, will have to get him to send me some pics. I am not 100% confident on fault finding heating systems so will do me the world of go and re wire it.

 

[Last plumber]

https://www.google.co.uk/url?sa=t&r...grams/&usg=AFQjCNFjsJcuWESICU-mMKNYXnAwssUi-g



Have a look at this link. There are lots of wiring diagrams on here that might help you if you're not used to it.

 

[rolyberkin]

I have rewired the whole heating system to which this post relates on Saturday and when I left (to travel to Essex from Lincolnshire!) everything was fine. I replaced all cables, there are three two port valves, one for heating, one for hot water and one for underfloor. There is Drayton twin programmer for CH and HW and separate wireless programmer for the underfloor. The UFH and CH are not currently switched on and my brother in law has just called to say that the pump is running when HW is put on timed or constant the pump is on constantly. I stayed overnight on Saturday and the water was set on constant and pump was not running continuously. I have today got him to turn off the two other zones and run just the hot water and the pump is running constantly, sticky valve or knackered microswitch or wiring faux pas? Anyone got any ideas?

 

[Midwest]

Without going back thru, could it be the heads gone on one of the valves? Had it on my own CH/HW system? Can't remember now, but nc or no contacts were u/s, causing constant demand to boiler.

 

[Leesparkykent]

I have rewired the whole heating system to which this post relates on Saturday and when I left (to travel to Essex from Lincolnshire!) everything was fine. I replaced all cables, there are three two port valves, one for heating, one for hot water and one for underfloor. There is Drayton twin programmer for CH and HW and separate wireless programmer for the underfloor. The UFH and CH are not currently switched on and my brother in law has just called to say that the pump is running when HW is put on timed or constant the pump is on constantly. I stayed overnight on Saturday and the water was set on constant and pump was not running continuously. I have today got him to turn off the two other zones and run just the hot water and the pump is running constantly, sticky valve or knackered microswitch or wiring faux pas? Anyone got any ideas?

Is the pump connected to the oranges of the valves or does the boiler have pump over run?

 

[rolyberkin]

Pump is connected to the orange wires, I have told him to turn off the UFH programmer and the heating side of the programmer and the hot water is constantly on, I think the next plan has to be to change the HW two port valve?

 

[Leesparkykent]

Pump is connected to the orange wires, I have told him to turn off the UFH programmer and the heating side of the programmer and the hot water is constantly on, I think the next plan has to be to change the HW two port valve?

Hmm that's strange...If the pump is running its getting 230V from somewhere which would also fire the boiler. Is there a separate wiring centre for the UFH heating?

 

[rolyberkin]

The Hot Water is constantly on when turned on at the time clock, i.e not cutting out, I think the boiler is also firing constantly. I have wired the UFH pump to a separate wireless time clock/thermostat as only one zone and working with what was there. Now starting to doubt my wiring although at the weekend everything seemed to be working okay?

 

[Leesparkykent]

The Hot Water is constantly on when turned on at the time clock, i.e not cutting out, I think the boiler is also firing constantly. I have wired the UFH pump to a separate wireless time clock/thermostat as only one zone and working with what was there. Now starting to doubt my wiring although at the weekend everything seemed to be working okay?

If the is the boiler constantly firing when the timeclock is constantly on or is it boiler constantly firing even when the timeclock is set to off?