Timer Firing Up Boiler for Water, not for Heating

[Mark Walsham]

Which traditional Vaillant do you have? Also just because the motor moves does not mean it is making the microswitch. When you put the heating on you are listening for a little click at the end. If you are not sure then listen to the hot water one which you know is working and you will hear the click. Do you have a multi meter and are you confident in using one?

I will check again in the morning as had a few beers and not the best time to do DIY (or is it the best time)?

Yes I do have a multi-meter and am Ok using it, checking for voltage or continuity, so I am guessing I would need to remove the cover of the valve and check the voltages?

The timer once it calls for CH issues a loud click, but not straight after the motor valve moves!!! So I will check!

Cheers, Mark.

 

[Harvest Fields]

Ignore the click from the timer for now. It is a little click when the microswitch makes. Also do not take the cover from the motor. Test for the other end of the cable. Should be a junction box?

 

[Mark Walsham]

Ignore the click from the timer for now. It is a little click when the microswitch makes. Also do not take the cover from the motor. Test for the other end of the cable. Should be a junction box?

Hmmm, the other end of the cable is squirelled behind the partition wall and may be my next mission tomorrow!

I am going to, as suggested, listen to the HW motor valve as I know that is working, and I will do the same for the CH one.

Thanks for the help, and will report back after tomorrow!

Cheers, Mark.

 

[Harvest Fields]

Hmmm, the other end of the cable is squirelled behind the partition wall and may be my next mission tomorrow!

I am going to, as suggested, listen to the HW motor valve as I know that is working, and I will do the same for the CH one.

Thanks for the help, and will report back after tomorrow!

Cheers, Mark.

Welcome to the wonderful world of Heating & Plumbing.

 

[Last Plumber]

I have a Climote (but re-badged by Scottish Electric) timer, which I think has developed a fault

Did it work before on Heating only or could you have only just noticed?
Does it have 10 / 16 program switch on the back? (I can't say I am familiar with Climote Programmers).

 

[Mark Walsham]

OK thank everyone so far, I do believe the culprit is the motorised valve under the boiler. I listened to this very carefully this evening, and when calling for CH, I can hear the motor running, but it is very slow. Much slower than when the call for the CH stops.

Additionally, after giving the manual lever a few cycles back and forth into and out of the locked on position, it now seems to work OK when the system calls for CH!!!

So, clearly this is the root of the problem and I am sure sooner or later it is going to give out completely!

Can I replace just the motor housing, motor and associated gubbins or do I need to replace the motor and valve unit?

As a very amateur DIY’er, I am filled with dread on draining the system to replace the valve, so any advice is much appreciated.

Thanks all,

Mark.

 

[ShaunCorbs]

Best to replace the whole valve and get a gas safe engy in if your unsure

 

[Last Plumber]

More often than not you can replace the motor.

It is 240V so be careful. Fuse pull, don't just switch off.
Always test it is dead, never presume.

I would take the motor out and see how the valve feels first. If it opens and closes nice and smooth and there are no teeth missing you could easily change the motor.

If in doubt, do what Shaun says and swap the valve.

 

[Harvest Fields]

OK thank everyone so far, I do believe the culprit is the motorised valve under the boiler. I listened to this very carefully this evening, and when calling for CH, I can hear the motor running, but it is very slow. Much slower than when the call for the CH stops.

Additionally, after giving the manual lever a few cycles back and forth into and out of the locked on position, it now seems to work OK when the system calls for CH!!!

So, clearly this is the root of the problem and I am sure sooner or later it is going to give out completely!

Can I replace just the motor housing, motor and associated gubbins or do I need to replace the motor and valve unit?

As a very amateur DIY’er, I am filled with dread on draining the system to replace the valve, so any advice is much appreciated.

Thanks all,

Mark.

Can you post a pic of the valve to see if the head will come off? You cannot remove it on some. How old is the valve? I personally wouldn’t change the whole thing if it is only a couple of years old.

 

[Mark Walsham]

Here is a pic of the motorised valve, a Honeywell unit, and for some reason there is no label or serial/model number on the unit! We bought this place about 10 years ago, and I think the boiler is approx 12 years old.

I am reasonably happy to replace the head unit myself as the wiring seems fairly straightforward, but my question is this...

Once the head is off, what is an easy way to check if there is wear to the valve itself?

As if there is wear, I shall get a plumber to come out and replace the head and valve in one go, but I hear that these valves are pretty reliable.

Anyway, as usual, any advice much appreciated!

Cheers, Mark.

 

[Harvest Fields]

Looking at the location of the valve I would say it looks awkward. I would get someone in to change it for you.