Possible Combi Boiler Issue!

[Mr Mcgoo]

Hi everyone. So i have the Viessman's vitodens 100-w condensing combi boiler and it would seem i may have an issue with water temps for both heating and DHW (domestic hot water). I have both set to 60c yet both my heat up to 75c then cool down to 65c to then heat back up again. This is well above the set water temp. Even if i drop the setting down to 50c the exact same thing happens. It acts as if the set temperature is ignored. My trouble is, i'm renting and if i call a gas engineer out and no fault is found i will be charged a call out fee £60, so would rather avoid that if possible. Anyone hear able to help before i risk a £60 loss before crimbo?

 

[Mr Mcgoo]

Thanks for the quick response. It has a pressure gauge and is reading 1.5 bar under operation. The manual states 0.8 bar minimum but no recommended pressure value. online i can see between 1-2 bar is the right value so i am all good there.

 

[Mr Mcgoo]

Have you had a look here - https://www.viessmann-us.com/conten...ions/original.media_file.inline.file/file.pdf

That is the manual for an older boiler. However, i already have the manual for my boiler thanks Shame that the manual does say anything in regarding to this issue nor can I find it online.

In that case, short of being able to find it as a common fault and a simple solution online, I don't have any other ideas, sorry

Not to worry thanks for your help anyway

 

[Mr Mcgoo]

That's seriously bad timing. Hope you get it fixed soon. I have no error code but my boiler is only 3 years old and has a yearly engineer come out to check for any issues. I am not due an inspection for another 8 months. Timing is just great. Right as the heating will start to come on

 

[Mr Mcgoo]

4 months ago i had a service and i get one every year.

 

[Mr Mcgoo]

Do they take that heat exchanger out like in my pic? And the main flow and return rubber pipes within the boiler? I’d think it’s that causing your problem mate

That was on the same Boiler a couple of months back, was doing the similar things which yours is !

i didn't pay much attention so will ask them to check it out next service. thanks for the info

 

[Mr Mcgoo]

ok so boiler has been fixed. turns out it has been locked to a setting and eco was disabled. any setting i changed wouldn't save but now it does and pressure is now at 2 bar while heating and 1.2 bar while off/eco mode. Strangely another issue has arrived. Really strong garlic/onion smell when the heating is on and a slightly lower garlic/onion smell with hot water running. This was a smell we had last year but was very light and we had a new foreign family move in next door thinking they maybe used a lot of garlic/onions. However the smell was mainly during the winter (highest boiler use). Winter again and the smell is worse. Anyone know what this smell is as the boiler is in the small bedroom and stinks the house out and is really bad for hours after the heating has been turned off.

 

[Mr Mcgoo]

bump

 

[Mr Mcgoo]

yeah seems that a gas leak is what other have said it could be. will get the plumber out tomorrow and check to make sure

 

[Mr Mcgoo]

Only when the boiler is running but it's not a plastic burning smell. Still waiting on my landlord to send someone out. He said to be safe he will get someone on it and have yet to hear back. So will give until Thursday and call back to make sure it's sorted in case it's something more serious.