Is this a Programmer fault?

[convclai]

Can anyone help?
I recently had a new 3-port Diverter Valve AND a new Cylinder Stat fitted to my central heating system because a problem had arisen whereby my CH was coming on okay when timed to do so but my HW was not.

Both are programmed to come on at 6am (I have a Drayton LP112 programmer and both CH and HW led indicators were illuminated).
Only when the CH ended its first cycle at 7.30am did the HW (which is programmed to be on just "once") then activate and heat up properly. It then appeared to "fall asleep" again and not heat the water up when required to do so until the CH programme came back on again at 5pm, and it then activated again properly.

Another factor was that the HW was heating up to VERY hot, way above the 60 degrees temperature set on the cylinder stat.

In spite of renewing the 3-port valve and the cylinder stat this problem seems to be persisting. The boiler ( a Worcester Ri) is working fine.
It does appear to be an electrical fault.
I now find myself having to go to the programmer and either switch ON or switch OFF the CH in order to get the HW circuit to "activate" and come on.

Is it possible that the programmer is at fault here?
If so I will get it changed.
One more question - is it possible that the programmer is somehow causing the HW to "ignore" the temperature setting on the Cylinder Stat and allow the HW to get so hot?
Sorry for the length of this query, but I thought the more explicit I made it the clearer it would be.

 

[twgas]

sounds like a wiring fault, although the programmer could be failing to switch the HW oneven though the indicator light comes on

 

[convclai]

Thanks, Mick.
If it is a wiring fault will the fault be traceable/fixable within the junction box that brings the stat, programmer and valve wirings together?

 

[Softus]

Yes - detail always helps, as as long as its succinct!

Do you have a multimeter, because you'll need one to diagnose the fault.

 

[convclai]

Thanks, Guys.
The annoying thing about this is that I have just recieved a bill for £340 for the work done to replace the Diverter Valve and the Cylinder Stat, and the problem is still there.
Should the engineer have tested for an "electrical fault" BEFORE getting stuck into the changing of valves and stats? When he first came to attend he initially renewed the motor on the replaced Diverter Valve, in case it was that which was the cause. So , I have had a bill for that job (£99) and a further bill for the new Valve and Stat job (£240). And the problem is still there.
Do I have any recourse to go back to them and get them to come to some arrangment over a further visit to rectify the electrical fault, which it does seem to definitely be?

 

[twgas]

I would be getting them back to rectify fault that they have not yet sorted, but billed you for.

 

[Softus]

Should the engineer have tested for an "electrical fault" BEFORE getting stuck into the changing of valves and stats?

Did you ask him to diagnose the fault, or did you ask him to change the valve and the 'stat?

When he first came to attend he initially renewed the motor on the replaced Diverter Valve, in case it was that which was the cause. So , I have had a bill for that job (£99) and a further bill for the new Valve and Stat job (£240). And the problem is still there.

If all that is true, then he has not competently diagnosed or fixed the problem. It's possible that you had/have more than one fault, but if you gave the symptoms and asked him to fix the problem then he should have tested the system and left everything working.

Do I have any recourse to go back to them and get them to come to some arrangment over a further visit to rectify the electrical fault, which it does seem to definitely be?

It depends on the remit that you first gave when you engaged him/them.

 

[convclai]

Thanks again, Mick.
Does it sound to you as if it's an electrical problem which can be fixed easily and quickly by a qualified heating engineer (given that it is a problem which has only presented itself very recently?).
And, as I asked previously, is the fault likely to be obvious within the junction box where all the stats and valve wirings come together ( which in my house is in the airing cupboard?)

Would an Electrician be able to fix it, rather than a heating engineer?
I have a pal who is a qualified Electrician.

 

[twgas]

many electricians are not so good when it comes to heating system wiring/fault finding - a decent heating engineer would, probably, be a better bet. this type of fault should not pose too big a problem for most engineers, or even a good DIYer, but testing components and understanding readings and test results seem too complicated for some.

 

[convclai]

Softus.
Hello. Thanks for your input.

I did explain the problem which had arisen (as detailed initially above) when the engineer initially called. The engineer immediately thought that the Diverter Valve was the "source" of the problem, rather than (as has turned out to be the case) an electrical fault. I only ask "should he have tested for an electrical fault at first instance?" He convinced me that if his replacement of the valve motor did not resolve the problem then it was likely to be a problem with the valve itself and it should be renewed.
The question of an electrical fault didn't seem to cross his mind.

Hence the bill totalling £340, and still not sorted.

 

[twgas]

anyone with a little common sense would do some tests to prove/disprove their initial suspisions.

 

[convclai]

Mick and Softus.
Many many thanks, guys. Appreciate it.

Just one question which is bothering me.
Is it possible that the Drayton LP112 programmer (if it is faulty) can interfere with the temperature of the HW?

As I say above, the cylinder stat is set at 60 degrees but the HW is heating up to considerably beyond that. If the programmer is where the fault lies can this lead to the cylinder stat being "ignored" by the faulty programmer?

 

[twgas]

if the wiring is wrong it could be that the programmer is bypassing the cyl stat and as such would appear to control the water temp, but the actual temp would be, in this case, controlled by the boiler stat.

 

[convclai]

Mick.
You're a gent.

It very much does appear, then, that the programmer is the culprit here.
Perhaps one of the "dry" joints on its circuit board has come astray and that's what is causing this prob.
Do you have experience of that sort of thing happening?

I have a pal who is going to come along and fit a new one (like for like) on monday. Hopefully that will sort it.
I will let you know.

 

[Softus]

It very much does appear, then, that the programmer is the culprit here.

No. You're now doing what your engineer did, i.e. just guessing at the cause of the problem.

The programmer will supply power to the circuit that opens the valve and thereby calls for heat from the boiler, with the thermostat calling the shots before the valve.

The components that could be faulty are:

1. Programmer;
2. Cylinder thermostat;
3. Valve (yes that's right, even though it's new);
4. The wiring between the components.

You need to check that each component is receiving power when you expect it, and not when you expect it not to. You might even have, or have had two faults. Or more. Guessing is a very expensive (and, for you, frustrating) method of solving the problem.

Perhaps one of the "dry" joints on its circuit board has come astray and that's what is causing this prob.
Do you have experience of that sort of thing happening?

That sort of thing is rare. More commonplace is a relay in the programmer fusing open or shut.

Get a multimeter and start fault-finding....