Vaillant ecotec plus 438 no heating or hot water

[noddy997]

The legendary problem has returned.

I have been advised it's due to condensation in the loft. And today the loft had 55-60% relative humidity but had not heating or hw. The garage had 60-70% where the boiler is located.

I've bagged up the wiring in the loft and put a plastic tub over it too to prevent any moisture entering the wiring few months ago but that hasn't sorted it. Had no issues in the summer it's only from Oct to April this issue happens.

Got 2 extractors that are vented in the loft void and will be having these vented through roof tiles soon and will have soffit vents put in. I've put in lap vents in the roof membrane for now but that's not helped much I guess. I did redirect the two extractor fans towards the soffit where there is a 6 inch hole from an old soil pipe that used to go through the roof.

 

[Harry Bloomfield]

I have been advised it's due to condensation in the loft. And today the loft had 55-60% relative humidity but had not heating or hw. The garage had 60-70% where the boiler is located.

Those humidity levels, if accurate measurements, are quite normal. Your heating, working or not, should not normally affect the humidity level in the loft, unless you have heating in the loft. Likewise, the garage.

The way to diagnose your problem, is as true now, as it was at the beginning of this thread....

By checking the voltages at the wiring centre, and reporting back - but you need to first check your wiring centre has been setup to the default termination layout, numbered 1 to 8, left to right, like the below diagram.

 

[noddy997]

Those humidity levels, if accurate measurements, are quite normal. Your heating, working or not, should not normally affect the humidity level in the loft, unless you have heating in the loft. Likewise, the garage.

The way to diagnose your problem, is as true now, as it was at the beginning of this thread....

By checking the voltages at the wiring centre, and reporting back - but you need to first check your wiring centre has been setup to the default termination layout, numbered 1 to 8, left to right, like the below diagram.

View attachment 357929

Wiring is all fine. As stated the issue is in the colder months not the warmer months. Both hw and ch work fine from April to end of sept. Come on straight away etc. As stated much earlier one of the live wires in the loft became oxidised due to condensation but the wiring is covered up now. The only wiring that is old and hasn't been changed is the cylinder stat one or the cylinder stat becomes condensed easily?

 

[Harry Bloomfield]

The only wiring that is old and hasn't been changed is the cylinder stat one or the cylinder stat becomes condensed easily?

What does 'becomes condensed easily' mean?

As a;ready pointed out, the way to diagnose it, is by checking the voltages at the wiring centre, when the system is faulty. The voltages at the wiring centre, give all the information needed, to indicate where the issue is. Measure between the N terminal 2, and all the other terminals, make a note of them, and report back the measurement of each.

 

[noddy997]

What does 'becomes condensed easily' mean?

As a;ready pointed out, the way to diagnose it, is by checking the voltages at the wiring centre, when the system is faulty. The voltages at the wiring centre, give all the information needed, to indicate where the issue is. Measure between the N terminal 2, and all the other terminals, make a note of them, and report back the measurement of each.

I've already done that.

As stated the issue happens in colder months. There isn't a fault with the system, pump, valve or boiler.

What I meant the loft gets condensation in the colder months and one of the wires becomes oxidised due to the condensation.

If a cylinder stat is faulty will it stop the HW or ch from coming on?

 

[Harry Bloomfield]

I've already done that.

OK, then posting the result of your checks, when the problem is apparent, would make it easy to diagnose. Why not do that?

What I meant the loft gets condensation in the colder months and one of the wires becomes oxidised due to the condensation.

What connections, or parts of your heating system do you have in the loft, which might be affected by condensation, or oxidation? Normally, the only part of a heating system, which is in the loft, are the tanks, in the case of an open vented system, or they sometimes fit the boiler up there, in the case of a combi boiler.

The problem only appearing during the colder months, rather suggests, it is a problem with the central heating part of the circuit..

If a cylinder stat is faulty will it stop the HW or ch from coming on?

Potentially, yes, but it would usually be evident year round, when ever there was central heating demand. Just to repeat - all becomes much clearer, if you simply post the results of tests, at the wiring centre terminals, when the issue is happening. Until that is done, the members of the forum, and you, will simply go round in circles.

Oxidation of wires, terminals, and contacts, in my experience, is usually the results of them being run at too high a current, rather than due to moisture, and/or contacts simply breaking up, due to mechanical wear and tear.

 

[noddy997]

OK, then posting the result of your checks, when the problem is apparent, would make it easy to diagnose. Why not do that?



What connections, or parts of your heating system do you have in the loft, which might be affected by condensation, or oxidation? Normally, the only part of a heating system, which is in the loft, are the tanks, in the case of an open vented system, or they sometimes fit the boiler up there, in the case of a combi boiler.

The problem only appearing during the colder months, rather suggests, it is a problem with the central heating part of the circuit..





Potentially, yes, but it would usually be evident year round, when ever there was central heating demand. Just to repeat - all becomes much clearer, if you simply post the results of tests, at the wiring centre terminals, when the issue is happening. Until that is done, the members of the forum, and you, will simply go round in circles.

Oxidation of wires, terminals, and contacts, in my experience, is usually the results of them being run at too high a current, rather than due to moisture, and/or contacts simply breaking up, due to mechanical wear and tear.

The heating does get used in April and September too when it's slightly cold too. It's not just the heating not coming on in colder months but the water too.

The readings won't be different from colder months or warmer months. The issue is condensation and oxidisation. It's only worth checking the readings if there is a fault with one or more components, again this fault would be all year round not just during colder months.

The wiring centre is in the loft, pump, valve, and tanks. Some of the pipework isn't lagged.

However, the issue is for 23 years everything was fine... I have replaced many things over the years.

A roofer has had a look at the roof and stated one of the vent tiles is defective and would be causing condensation.

 

[Harry Bloomfield]

The readings won't be different from colder months or warmer months. The issue is condensation and oxidisation.

Well, if actually know what the issue is, you should be able to resolve..

 

[noddy997]

Well, if actually know what the issue is, you should be able to resolve..

It's only worth checking the readings if there is a fault with one or more components, again this fault would be all year round not just during colder months

Sometimes I do wonder whether some members on this forum just get a kick out of trying to waste peoples time...

 

[Harry Bloomfield]

It's only worth checking the readings if there is a fault with one or more components, again this fault would be all year round not just during colder months

The only time it is worth checking, noting down, and reporting those values, is when the issues occur. When you do not have the issue, then the recorded values will obviously be correct.

Sometimes I do wonder whether some members on this forum just get a kick out of trying to waste peoples time...

Quite the contrary - you have had this thread running now for several years. During that time, a number of very experienced and qualified people, have tried hard to help you work out what is going wrong with your system, just as I have recently done. Rather than taking the advice, you have chosen to ignore it, and go off on a complete wild goose chase. That is your choice, of course, but don't expect anyone to join you on that folly.

 

[noddy997]

The only time it is worth checking, noting down, and reporting those values, is when the issues occur. When you do not have the issue, then the recorded values will obviously be correct.



Quite the contrary - you have had this thread running now for several years. During that time, a number of very experienced and qualified people, have tried hard to help you work out what is going wrong with your system, just as I have recently done. Rather than taking the advice, you have chosen to ignore it, and go off on a complete wild goose chase. That is your choice, of course, but don't expect anyone to join you on that folly.

Firstly the thread was created last Nov, it's 10 months old not number of years. If you can't get such basics correct what advice will you offer?

You don't seem to grasp the fact that for a number of months of the year everything works fine without any issue. Components are designed to work during cold and hot days. When everything has been tested and works then there will be other factors, which you seem to refuse to accept.

Your attitude is appalling and cocky and ignorant. I didn't ask you to reply you did yourself. You seem to ignore what people say and have a tantrum when people pull you up. Perhaps get a new hobby as you've been here since 2018. Jog on

 

[Harry Bloomfield]

Firstly the thread was created last Nov, it's 10 months old not number of years. If you can't get such basics correct what advice will you offer?

Correction accepted, my apologies for that error.

You don't seem to grasp the fact that for a number of months of the year everything works fine without any issue. Components are designed to work during cold and hot days. When everything has been tested and works then there will be other factors, which you seem to refuse to accept.

I understand that, but without following the advice offered, there is not much anyone can do other than second guess at the problem.

When everything has been tested and works then there will be other factors, which you seem to refuse to accept.

That is simply not true, you have been asked to carry out the most basic of tests, at the wiring centre, when you have the issue, but for some strange, incomprehensible reason you seem unwilling to do.

 

[noddy997]

Joys of the ignore button...

 

[Harry Bloomfield]

Joys of the ignore button...

The thanks you get, for trying to help some people out!