Vaillant eco TEC plus 418 coming on outside timed hours

[Kent212]

Hi
I had a Vaillant eco TEC plus 418 boiler installed last month. It seems to be working fine except that every day/ night it comes on once briefly for about 10-15 seconds outside the timed periods and then switches off e.g. 3.10pm on Wednesday, 2.10pm on Thursday etc. This doesn't matter during the day but is a nuisance at night as it is waking me up. I contacted the plumber who installed it and he says he hasn't come across the fault before. No fault codes are showing.He returned it to 'factory settings' but the problem has continued. I contacted Vaillant who said it is not to do with the boiler but the wiring.

If anybody has any ideas I'd be grateful to hear them.

 

[muggles]

Could well be a sticking zone valve

 

[Mottie]

I had a Vaillant eco TEC plus 418 boiler installed last month. It seems to be working fine except that every day/ night it comes on once briefly for about 10-15 seconds outside the timed periods and then switches off e.g. 3.10pm on Wednesday, 2.10pm on Thursday etc. This doesn't matter during the day but is a nuisance at night as it is waking me up. I contacted the plumber who installed it and he says he hasn't come across the fault before. No fault codes are showing.He returned it to 'factory settings' but the problem has continued. I contacted Vaillant who said it is not to do with the boiler but the wiring.

If anybody has any ideas I'd be grateful to hear them.

I had exactly the same problem when my Vaillant Ecotec plus 418 was first fitted. If you are using anything other than Vaillant controls (which all run on 24v), the installer has forgotten to remove the 24v link.

 

[Kent212]

Thank you very much. Yes, my controller/ timer is a Drayton Lifestyle so hopefully your solution will work. Plumber returns on Monday so fingers crossed!

 

[ianmcd]

+1 the 24V link has been left in , very easy fix

 

[Mottie]

Thank you very much. Yes, my controller/ timer is a Drayton Lifestyle so hopefully your solution will work. Plumber returns on Monday so fingers crossed!

I removed mine myself while waiting for the installer to return. Very, very easy.

 

[Kent212]

I’m now wondering if there is an additional problem with the wiring for this boiler, besides the 24v link. The boiler is timed to come on for an hour in the morning and at 6.30pm in the evening, going off at 9pm. The boiler is active until about 7.45pm i.e. displays the radiator symbol flashing with the flame symbol on the left hand side and the bar level below it but then goes quiet and the display looks like it does outside the timed period, as in the picture below

.

Around 8.00- 8.30pm I use a fair amount of hot water. My understanding is that HW comes from the HW cylinder in the airing cupboard and so would expect the boiler to fire up again as cold water refills the cylinder and the internal thermostat is telling it to heat it up as it’s supposed to be on until 9pm. That isn’t happening and the display continues to look like it does in the picture and looks the same even after 9pm when it’s supposed to be off anyway. Any thoughts would be really appreciated, thank you.

 

[Mottie]

I leave my hot water on constant - on a well insulated cylinder it makes very little difference price wise. It depends on what the temperature is set at on the cylinder, size of cylinder, amount used etc.. I still say it’s the link. Turn the power off to it, flip the cover off yourself and check that link. Honestly, it’s really easy. I only found out about it when I phoned Vaillant up while waiting for the engineer to return. The bloke I was talking to at Vaillant stopped me halfway through describing my problem and said "24v link". When I said it was a Vaillant approved installer (I know, means nothing!), he said "They all bloody forget to remove the link". It’s so common.

 

[picasso]

Might be the pump anti seize which spins the pump for a few seconds every 24 hours, try turning the mains off to the boiler for 12 hours and see if it still happens.

 

[Kent212]

The plumber arrived today and rang Vaillant's technical helpline. It is the pump's anti-seize mechanism which is making it come on briefly every 23 hours, including outside timed hours - cheers, picasso! I'm gobsmacked that Vaillant has deliberately installed a feature which will wake people up every night for one week in three when their selling point is that it is the quietest boiler on the market! Absolutely ridiculous and incomprehensible. You cannot override it or alter the time it comes on. They don't even mention it in the customer pamphlet or the instructions for the installer. Also, the staff on the Vaillant helpline for customers clearly didn't know about it either. Thanks anyway to everybody who replied. I'm now going to write to Vaillant's Chief Executive and ask them what they are playing at - don't they have customer focus groups - I bet this would have got the thumbs down!

 

[Gasguru]

They've had the exercise program ever since the boiler was launched AFAIR...but the implementation appears to be a bodge....it shouldn't be doing it if there has been a previous heat demand in the last 24 Hrs and of course with the software/displays on todays models it would be dead simple to program in a time to exercise.
Most boilers have the feature as it reduces breakdowns..ie. seized pumps after returning from holiday etc.

 

[ianmcd]

As above the Pump Kick should only come in if there has been no demand on the boiler for 24 hours

 

[Mottie]

The plumber arrived today and rang Vaillant's technical helpline. It is the pump's anti-seize mechanism which is making it come on briefly every 23 hours, including outside timed hours - cheers, picasso! I'm gobsmacked that Vaillant has deliberately installed a feature which will wake people up every night for one week in three when their selling point is that it is the quietest boiler on the market!

I can’t say I’ve ever heard my one do it and it’s been in for two years now.

 

[Kent212]

Sounds like a fault as boiler in always on within a 24 hour period so anti-seize isn't needed. Also explains why my plumber had never come across the problem before. Am concerned that the the technical helpline says this is normal and can't be changed! Will wait for Chief Exec's reply..

 

[Harry Bloomfield]

I have just put a link to this thread, into my own thread where I asked about this very same issue - https://www.diynot.com/diy/threads/vaillant-ecofit-418-purge-cycle.517279/#post-4715516

Thanks to Gasguru for the answer...