Problem with Valliant Combi Boiler

ahll

I think I might have a problem with my 4yr old Valliant combi boiler. The hotwater seems to be hot one minute and cold the next ! It seems if you reset the boiler (turn it off then on) then the water seems to be hot until the next time.

Can anyone tell my what the possible problem is and/or how I may sort it out ?

jos22

Can't help with your problem but a posting here http://www.diynot.com/forums/viewforum.php?f=7 should get results.

ANGELADIX2

I BOTHER A WHILE BACK MINE KEPT COMMING UP WITH F21 NEEDED NEW VALVE BUT OK NOW,have u check to see what faults are comming up ????

ahll

I dont believe my boiler is coming up with an error number as there is no place for it that I can see. All there seems to be is screen with a temp in it 48 deg.

There does appear to be a green flashing light(sometimes flashing) with an (I) under it a red light(underneath a pilot light with cross through it) and an amber light(nothing under amber light).

ahll

Even though there doesnt seem to be an error number coming up. There does seem to be some relation between the heating being on and the water not being hot. It appears whent the central heating is on the water at first runs hot and then seem so go cold !

Anyone got any ideas as to what could be causing this ?

sd006c3768

I have a similar problem caused by two leaking radiators. Check the valves and walls behind all rads for water.

oldandhappy

ahll wrote:

I think I might have a problem with my 4yr old Valliant combi boiler. The hotwater seems to be hot one minute and cold the next ! It seems if you reset the boiler (turn it off then on) then the water seems to be hot until the next time.

Can anyone tell my what the possible problem is and/or how I may sort it out ?

We took out a service contract because Valliant boilers seem really expensive to repair although very good boilers...We have had a problem in the past where the rads would heat up when it was on hot water only and the engineer fitted a new part that I remember cost over £100. Another occasion we had an intermittent fault that could not be sorted easily(electrical circuit of some sort) so then again a new part was fitted. Valliant have mailed us twice recently offering Winter service contracts...not impressed though...all year cover is needed for sure. Mrs Happy

susieb1967

HI
We have this problem also! If the heating is on ...forget gettting hotwater!. You have to wait for the boiler to cool down from your heating use before it will let u have hot water! My fault is the valve is stuck, so you can only get one function at a time, if you put your hot water on when rads are on it may sound like the hot water is kicking in but actually it will be heating the rads while your running the taps---- a complete waste of money and seriously frustrating!!
It sounds very much like u need the diverter valve changing, and they are about £100. However they were selling some types on ebay for £60ish if you've got a bit of KNOW HOW!

BTW Some of them are not sealed units so you can actually get inside the part to change the valve only.... this would be pennies! But I think most of the new boilers come with sealed diverter valves ( clever Valliant:mad: ) so this may be worth checking, your local plumb merchant will know if you let them know your model number.

Also I was told that to constantly keep turning taps on for a little blast of hot water, e. g. when washing hands, is constant wear and tear on the valve so you should get in the habit of going for the cold tap first!!- Doubly money saving!!;)
Hope this helps!!

pandaonmyshoulder

Have struggled with our boiler since we had it fitted 4 years ago, Valiant have been out dozens of times and fixed Anyway taking the plung on Wednesday and having it taken out.:j

Mr_Meanie

pandaonmyshoulder wrote:

Have struggled with our boiler since we had it fitted 4 years ago, Valiant have been out dozens of times and fixed Anyway taking the plung on Wednesday and having it taken out.:j

And just as matter of interest replaced with what? and why?

ahll

Actaully now you come to mention it yesterday the rads got really hot when they weren't even suppose to be on. I bought Valiant because I believed that they were of very good quality and reliable. Seems quite a few people are having similar problems.

susieb1967 I have never done any work on my boiler and so I am not sure about trying it now incase I loose all my heating and wot hot water I have. Can you work on a bolier without being corgi registered. How can you tell if your boiler sealed ?

Is the Diverter Valve different than the value change only ?
Do you have to do something to stop the possibility of water coming out of the boiler when changing the value ?

I am not totally sure what you are saying here could you explain it in more detail
"It sounds very much like u need the diverter valve changing, and they are about £100. However they were selling some types on ebay for £60ish if you've got a bit of KNOW HOW!