Powerhead click causes CH to turn off - but head replaced!

[chad5k1]

Hi All

When the boiler is running the Honeywell Mid postion valve started "clicking". The clicking noise is the microswitch being hit then the valve moving off it and then moving back and making contact with the switch again. A sort of rocking motion that means the microswitch is being hit every second or so.

It happens when the HW and CH is on. When only the CH is on there is no problem.

I have replaced the powerhead and tested it works ok as per the instructions. When it all first turns on everything seems to work fine and the valve opens correctly whenever i ask it too, e.g. turn the HW stat up or down and the same for the room stat.

BUT after about 1 hour with both HW and CH on the powerhead starts clicking (in the middle position) and the pump and CH turn off. To get the CH back on I have to turn the HW off either by the stat or the programmer.

Anyone got any thoughts?

Could it be the HW stat on the cylinder, i know the immersion heater was changed at some point in the past so perhaps the last one was faulty and fired the HW stat on the cylinder?

Thanks in advance
Rich

 

[confuscius]

Hi, Ive jsu had a similar problem. Is your new valve the Honeywell and if so have you swapped around tank stat wire C and 1 and run a wire between the grey wire and HW OFF?

 

[chad5k1]

I did a direct swap on the honeywell powerhead.
So all the wiring is as it was previously. I'll check the wiring but I'd be suprised if it was wrong as at some point the system was working fine.
Did you have to change the wiring as you suggest to fix it?

 

[confuscius]

Hi, When you changed your valve for the V4073A did you switch the wires C and 1 in the Cylinder Stat and run a wire from the grey wire in the wiring centre block to the Hot Water Off position on the Programmer. I just spoke to Honeywell Technical and the adviser said the valve ticking on my system is caused by not changing the Stat wires over. I'm just going to do mine now. Let me know how you get on. I am NOT a Heating/Electrical Professional. I am merely sharing my experience in this area. Good luck!

 

[chad5k1]

Changing over c and 1 didn't help, in fact it sent me backwards as it made everything start up when i turned the stat down! LOL

I've replaced the cylinder stat with no joy either.

The only strange thing that I can see is there is no wire other than N to the honeywell valve from the pump, but there is a wire from the pump to the boiler. I don't see how this could work and I'm sure there should be one looking at the diagram. But it does turn on and work for almost an hour, i think perhaps when the HW reaches temperature it goes pear shaped and he valve starts clicking in the position and turns everything off.

I know I should be able to get my head round this but I can't, perhaps it is cos I always start looking at it after dinner and glass of wine.....

 

[chad5k1]

thought I'd post the fix for anyone that may comes across this.
It appears it was wired up incorrectly.
Looking at the wiring and how it was supposed to be I have no idea why it was wired up in the manner that it was, or how it was working.

I effectively took the wiring apart and rewired it all. It now has been working a treat for a week or so.

The only thing I'm not sure about is a yellow live wire that comes from the boiler. At the moment I've not wired it up to anything and just left it safe, but I can't imagine what it should be connected to, it just seems to be an extra wire.

 

[bengasman]

what is the code on the replacement module?

 

[gas4you]

Whats the make and model of the boiler?

A lot have permanent live and switched live and some have the live to the pump so the boiler controls the pump.

 

[chad5k1]

Not sure what you mean by replacement module bengasman.
Gas4you, the yellow live was to the pump originally, but the pump had no connection to the valve hence why ti was not working me thinks. It is a potterton netaheat profile of some description.
Thanks

 

[twgas]

profile should have the pump wired directly from it as it has a pump overrun, to dissipate heat build up after stats shut down

 

[chad5k1]

Thanks, so the profile has four wires from it.
Red = Valve, HW stat, Pump
Blue = valve, pump, room stat
Earth = Earth
Yellow = nowhere

Previously the yellow was wired to the pump and the pump was not connected to the valve at all.
Are you suggesting that I wire the Yellow directly to the pump live or fed it into the same connection as the Red?

 

[twgas]

you should have, at the boiler
permanant live, connected to live from main spur
switched live, connected to orange from valve
pump live, connected to pump
neutral
earth

 

[chad5k1]

You are right, what I was missing before was any connection from the pump to the valve.

This caused the problem referenced in this topic.

So, I'll rewire yet again so that;

permanant live = live from main spur DONE
switched live = connected to orange from valve DONE (i think?)
pump live = connected to pump (not yet)
neutral = DONE
earth = DONE

Only problem is which one is the switched live, red or yellow, I'll have to get the multimeter out, but i suspect it is Red as everything appears to be working at the moment. I suspect the boiler is not getting the pump to overrun.
So do I run an extra cable to the pump live from the Yellow, or can i just patch this into the same connection as the Red - which would mean it's connected to the valve also so I guess not?

 

[twgas]

cant say which colour does what, there is no right way as such, but all live wires should be brown or red, or be sleeved such, so as to tell anyone they are live. and no you cant have pump and another live joined up.

 

[chad5k1]

Oh bugger.
So you are saying the potterton has to have a connection to have live connection to the pump. But if that is the case it means I've have to disconnection the valve from the pump and flaming clicking will come back.
What will happen if I don't have a live connection to the pump from the boiler, just the switched as at present?