Vaillant EcoTec: vibration from the pipes, S40 "comfort protection active" permanently on
Anonymous user 15/03/2024 - 2.47 PM
I had a new Combi boiler (a Vaillant EcoTec exclusive green IQ 843) installed a few days ago replacing a previous system one. My flat has 2 bathrooms on two floors with 2 showers and 1 bath.
Heating works, and hot water mostly works as well but there's something that kicks in when we shower that is not good.
After a few minutes using the shower (say, 4-5) a vibration/buzzing noise starts being audible through the pipes, and the boiler goes from outputting water at the configured 65C down to a value that constantly swings between 48C and 54C, resulting in perceivable changes of the water temperature coming down the shower.
At some point in one case the boiler completely stopped outputting hot water, and the display showed 17C with the tap icon constantly on (meaning "draw-off mode with no burner") as far as I can see.
I've noticed that the boiler live monitor constantly reports state S40, which is "comfort protection active", and according to the maintenance manual (https://www.vaillant.co.uk/downloads/aproducts/ecotec-exclusive/news/combi/ecotec-exclusive-installation-and-maintenance-instructions0020193968-03-pdf-1413944.pdf) should be a temporary mode (but for us it's constantly on).
Our installers suggested that there might be a TMV "somewhere" that might be malfunctioning, but we couldn't find one and before starting to open floorboards and break walls/ceilings I would want to make sure there is not a more plausible explanation. Someone advised me to turn the cold feed to the boiler off and try to open the hot water taps, saying if I got water out it would mean I have a TMV, but none of the taps/showers actually get any water when opening the HW tap in that case.
Does anybody have any idea what might be involved here?
Are you a tradesperson and able to answer this question?
Hello,
I would say that if all the hot taps are ok then try running them for 5 mins each like you do with the shower and if still ok, it means that the hot water side of the boiler is working ok. The issue is then the shower.
The showers will likely have their own thermostatic mixers in each. If the shower hot is closing down the hot side of the shower too much while your (very powerful 43KW) boiler is firing for hot water then you might start getting shuddering in the pipes as pressure and heat try to pass through a shower mixer valve that is closing down in error. The boiler, being intelligent, might not like this and recognises something's struggling or heat is building up and so modulates the flame down or off entirely.
Is it just the one shower that does this or does the other shower do the same? Try the other shower for a few days and see if it happens with it.
If both do the same, are they suitable for a combi boiler and suitable for this particular (special) combi? That would be a question for the shower manufacturer and/or Vaillant Technical. 43kw is a very powerful combi with a very good flow rate of over 17 litres per minute. There may be shower restrictors or inserts that need to be fitted or removed as this is a different type of water system to your old.
The Status code you are getting is when the boiler senses something's wrong and goes into a safe mode to protect itself. It may clear itself or it may need action to reset it. Again, Vaillant Technical would tell your installer this.
Bear in mind that you have a minimum of 5 years guarantee on this model, 7 years if your installer was a Vaillant Advance installer and 10 years if a Vaillant Advance installer and a Vaillant filter kit was fitted.
Also, electronics can go faulty at any time (even from new) and the boiler could have some coincidental other (electronic) issue where it is never going to come out of the protection mode. ie. it's possible to have more than one issue.
You should possibly get you installer back to phone Vaillant Technical from site and test.
If you phone Vaillant and say that you are getting shuddering and this code you cannot reset then they may come out under warranty to have a look. They will be able to prove onsite if it is their boiler at fault of if it's an external plumbing issue.
Hope this helps.
Answered10 May 2019
14
Anonymous user
Why are you trying to fix the problem with your boiler? Should your installer not be back rectifying the problem? Sounds like the installer is out his depth as there wouldn’t be a inline TMV on the shower supply! It sounds like the thermostatic shower is causing the issue with the boiler if all the taps run fine, with a new boiler being installed there’s a good chance there is debris in the shower filter, reducing the flow and causing the water hammer to occur, without beeing there in person it’s hard to diagnose the problem, good luck with it and report back what the problem was,
Answered8 June 2019
0
Anonymous user
I agree with the other comments. I certainly do not believe it’s an issue with the boiler, in fact the boiler is doing what it should when it detects a problem . Everything points to the shower , especially if it thermostatic . The vibrating noise is a water hammer due to the thermostat on shower closing down hot supply to it slightly.
