OK cold radiators on christmas eve at 8:00pm anyideas ???

[Wombly1]

background up unitl two hours ago fully functioning system no problems

CH is a vented gas indirect using
Wikes LW60ci
Grundfos pump p/n595 25600 pc 0246 ip 44 class h max 10 bar three speed.
Channel plus xl h21 timer and honeywell thermostat.

Noticed that the heating wasn't on when I got in from work.

restarted the timer three way valve states
Thermostat light comes on boiler does nothing

test for power to the pump didn't seem to be anything
everything else seemed to test for power and function ok.

I'm no CH engineer and probably broke a million rules but to test if the pump had died I disconnected it from the junction box having noted that it take mains voltage I added a plug set everything to full and on and plugged it in. Hey presto everything came to life.

so now I'm really confused re wired the pump back and it does nothing.

any ideas guys would be really apreaciated

 

[seco services]

what motorised valve have you ?
one of these

 

[MANDATE]

I'm thinking it may be another of these 3 port valve problems.
Do I take it there is no problem with HW only.
What happens is that when the valve moves to CH only a micro switch is triggered that lights the boiler, so the micro switch might be the problem.
But it could be the valve is not moving to CH only, in fact the valve may not be moving away from HW only.
What make 3 port valve do you have.

 

[Wombly1]

thanks for the replies chaps.

the valve is a standard Landis and Steafea and you see the little arm move across when the power is turned on to the program timer.

And yes if I hit the boost button on the hot water the boiler flashes up fine.

Do you have a diagram of the wiring loom for how this solution is suppossed to be connected up. We only bought the house a few months ago and I'm finding all sorts of DIY points of interest.... it would be usefull fo rme to have diagram of how the parts are suppossed to talk to each other.

 

[Wombly1]

Are we talking about a micro chip in the three way or the boiler?

is there any way to do an issolation test on the switch to prove this is the problem.

Is it a replasable as a part or is it part of a unit (assuming you mean the boiler) that would involve booking a qualified fitter ie i don't beleive im allowed to go inside the boiler itself ( no offence but i really don't fancy the cost of that over christmas/newyear)

If I can buy it myself would I be able to get it from a plumbers merchant or would it have to come from Wikes

and ofcourse how much would I be looking at.

 

[gas4you]

Not a boiler fault then. The 3 port valve head sounds like the microswitch has gone inside it.

Unfortunately I think you will have to change the entire valve with this make

 

[Agile]

There is a microswitch inside the motor valve and this connects the grey and orange wire which provides a signal to start the boiler and pump.

It sounds as if the switch is operating in the hot water position but not the CH position and unclear whats happening in the CH+HW position.

Usually the fine clearances are not quite correct and sometimes you can make it work on a temporary basis by sticking a little piece of thin cardboard on the operating lever to encourage it to make the switch.

Tony

 

[Wombly1]

Guys today I isolated the the thermostat and connected the pump to the program unit so that the boiler and pump cam on on the timer regardless of the thermostat and it worked. I sat down and had a hard think about what this meant and decided to see if I could trace the cable from the junction box through the boiler. Doing so I went through and tightened every connector not that there was really any chance I thought that this would make any difference but then nothing else made any sense either surely if the CH would work with the pump on manual it couldn't be the 3way because this would mean the radiators wouldn't have got hot when even though the pump was running wouldn't it?

Anyway the only thing that seemed to be the issue was power to the pump when the thermostat which was showing power ie the light was coming on was not getting there. traceing the cabling I found a connector that although not entirley lose was not tight either. I reconnected everything and it allcame back to life.

I would like to thank everyone who took time to forward sugggestions though as I was at a complete loss and resonably panicked on christmas eve.

thanks again and Happy new year to everyone.

PS I guess it could still be the three way valve and it justs an intermitant fault no doubt I'll find that out on new years eve...

cheers....

 

[gas4you]

If only all faults could be fixed this easily

 

[Tipper]

Great that it's going again.

BTW other intermittant faults can occur which may eventually be found to be the Horstman 3 channel timer. They have a battery within and when it dies the programmer loses control of itself (a touch of Alzheimer's!) and doesn't control its relays properly. The later ones have a replaceable battery the earlier ones don't.