Baxi 105e pressure rising - wierd!!!

[slamdunker]

Hi
We've got a baxi 105 instant e combi. The pressure keeps rising, about 1bar a week at present. I thought the filling loop valve might be passing, so I took it off, and bizarrely the pressure continues to rise. I can only assume water is crossing over somehow from the dhw system into the ch system at a very low rate. Could it be the diverter valve diaphragm split, or is this unlikely?
Has anyone met this before, and if so what was the outcome?
Hope you can help
Cheers
Dunk

 

[al-yeti]

Thinking diy hmmmm

The divertor valve i guess would be the only other mechanical path for the water to cross over, and i guess the pressure is increasing close to the mains water pressure level, so if it aint the filling loop which if its external then you could disconnect it to prove the point



of course i could be talking nonsense

I only replied to this cos no one else did hope someone replies to mine!

 

[Rob]

If it rises even with the boiler off then its likely the plate heat exchanger.

 

[Slugbabydotcom]

Assuming theres no other mysterious connection of water to the system the only perceivable route is through the plate heat exchanger as rob says

 

[baxpoti]

Part Nos. required

1 x 248723
4 x 248049

 

[slamdunker]

Hi
Thanks for the promp replies guys, much appreciated.

Ok if it's the plate heat exchanger, then where is this, is it accessible?
If so, then is it a professional job to repair or can it be DIY'd?
What should I expect to pay for the parts?

ANY advice would be most welcome.

Cheers
Dunk

 

[Vic Spanner]

then where is this,

Behind the pump and 3-way valve..

is it accessible?

No..Removal of gas valve will be required (CORGI ground)

What should I expect to pay for the parts?

Guess about £60.00-80.00 big uns

Make sure the ex vess is drained as well..Bloody hot water in there

 

[sam100]

i think it might be your expansion tank. i have exactly the same problem. had two plumbers look at it. called out Baxi who are without a doubt the worst people i have ever dealt with. having paid them a fortune, they could not have been less helpful. their suggestion was to screw another expansion tank to the wall next to the boiler (its in a bathroom) and slave it to the main one. what a joke! health and safety prevents them from using a ladder, so save your money and don't use them!!!

you also need to address this problem quickly, as it can ruin the pump if you leave it too long. big bill for labour, unfortunately.

 

[LUNAT]

HI

change DHW heat EX and the problem will be solved .
and you do not have to remove gas valve for this.
i replaced few of these.

 

[sam100]

how much work is involved to do these jobs?