vaillant 824 water temp fluctuation!

[psaila]

hi all i have a vaillant turbomax 824/2e my water hot water temp goes up and down from around 55 to 78 degrees then back down etc. i have been reading many peoples posts on similar problems and decided to change the diverter valve. whilst changing the valve i have taken the heat exchanger out soaked it with viakal and removed a fair bit of debris. trouble is it has stayed pretty much as it was before temp going up and down! does anyone have any ideas?

thanks in advance

 

[psaila]

have also noticed that as the temp goes up and down it sounds like it keeps relighting itself may be normal but thought id add
cheers

 

[bellairaphon]

try changing the ntcs

Nath

 

[psaila]

thanks for the reply there are three of the sensors which would you suggest? or all 3? i tried swapping the flow and return ones over and that didnt help
cheers

 

[AkuraEngineer]

how you came to the conclusion its diverter is beyond me?

 

[psaila]

to be honest im only a home diyer not a plumber, read a few topics on this site and it seemed to tie up! not to worried the valve was only £50 and can only do good in the long run. so do you have any ideas?
thanks daz

 

[AkuraEngineer]

yeah i know exactly whats wrong with it its one of 2 things at a stretch possibly 3 however DIY is great just not when it comes to boilers repairs

theres actually people like myself who devote their profession and life to repairing boilers its the very reason why i can put bread on the table so if i was to give out free advise all day im mearly shooting myself in the foot

boiler repairs is doesn’t not start and end with the physical side its not about whether or not joe public can physically do the job themselves its a technical job so regardless of how easy it physically is to do the job you still need the knowledge, training, competence and experience to enable you to do the physical part of the job in the first place, something that normal joe public like yourselves don’t seem to appreciate

i would offer you some advice if you need a hand understand customer controls such as the time switch the thermostat knobs or understanding how to use the boiler but asking for advice to repair your own boiler is a pi55 take

 

[psaila]

i get what you are saying, but i thought that is what this site was about? helping each other. and yes it would be greatly appreciated for your input. i also have mouths to feed and with my current work not too good thought id try to save a few £££ and try it myself.
cheers daz

 

[Agile]

Yes, but you have already spent £50 and not cured the problem.

I would say you have wasted £50.

Had you asked for advice BEFORE you started you would have had a better chance of solving the problem at little or minimum cost.

I am always sceptical about people who dont put any information in their profile and hide their location by choosing an unknown or obviously incorrect place.

 

[psaila]

yes i have wasted £50 and dont realy want to waste any more, whilst registering i couldnt find uk so selected other. for you information i live in portsmouth down south.
and yes i should have asked first dohh!

 

[Agile]

Thats much better! We dont know who you are but we do know WHERE you are!

Web diagnosis is always something of a gamble and there is nothing better than being in front of a boiler and having good diagnostic skills.

However, I think that your plate HE is blocked.

Household cleaners are never going to be strong enough as women and children use them.

Assuming its the primary side blocked then you will need citric acid in a warm solution shaken around and left to stand with regular shaking for a few hours. You can buy it in many Indian food stores in packets or in a large tub for plumbing use for about £25 as Fernox DS40.

It would only normally be the secondary blocked if you have had a dripping tap. In that case you would need hydrochloric acid at about 5-10% solution which has to handled carefully and suitable hand and eye protection used so less advisable.

Tony

 

[psaila]

thank you for the reply tony,
i work opposite a metal treatment factory they deal with lots of chemicals and acids maybe ill ask if they have anything suitable? would this be a good idea or do you think the stuff they have may be too strong?
regards darren

 

[Agile]

I cannot say as I dont know what they might offer you!

I would say stick with citric acid!

Tony

 

[psaila]

Thanks tony I'll get some and try tomorrow, I'll report back
thanks again

 

[psaila]

just like to say a huge thanks tony, i got some cleaner from a local plumbers merchant today. soaked then flushed repeated for 6 hrs and now the water temp is constant and hotter than i ever remember it being!
thanks again
daz