BAXI 80E COMBI RISING PRESSURE

[mmalone]

Guy's .. quick one for you's..

Mate called tonight at a Baxi 80e combi.. hes an engineer but works on Meter installs so not into FF...

PRESSURE WAS RISING...

Usual checks of exp vessel done, called me back saying pressure was rising when system not running, advised to check filling loop and see its not passing.
This wss not passing and pressure still rising when disconnected, he shut off the mains it stopped rising.

My only thought is the heat exchanger must be cracked and mixing mains pressure into the sealed section...

This model has the plate heat exchanger and told him this is the most likely component that will need replaced as its the only section the mains passes through for the DHW...


anyone agree / disagree or had this problem before ???

 

[Mikeyboy]

You are most cetainly correct in your assumption ,D.H.W. ht . exchanger is passing thro : to heating side of appliance . New plate heat exchanger required . Cost from parts centre is relativeley cheap .

 

[Mikeyboy]

Forgot to mention , that I was previously employed by Heat Team , common problem on the 80 .

 

[mmalone]

Forgot to mention , that I was previously employed by Heat Team , common problem on the 80 .

cheers mate.. appreciate the quick reply.. will let him know to go ahead and replace...

 

[Agile]

You said he had "shut off mains" but you did not say where.

Thias should ONLY be done at the CW inlet to the boiler as there CAN be other causes.

All these are unlikely but even a leaking plate is very rare. I see about one every 15 months in about 3500 boilers.

Quick and easy to replace but itsw important to correctly diagnose it first.

There is a second "reverse" check. Close off the CW inlet and disconnect the DHW out pipe. Any leakage will be seen as dripping system water from the DHW out. IF you wanted to demonstrate this to a trainee you could put colourant in the system water.

Tony

 

[mmalone]

You said he had "shut off mains" but you did not say where.

Thias should ONLY be done at the CW inlet to the boiler as there CAN be other causes.

All these are unlikely but even a leaking plate is very rare. I see about one every 15 months in about 3500 boilers.

Quick and easy to replace but itsw important to correctly diagnose it first.

There is a second "reverse" check. Close off the CW inlet and disconnect the DHW out pipe. Any leakage will be seen as dripping system water from the DHW out. IF you wanted to demonstrate this to a trainee you could put colourant in the system water.

Tony

Tony yes it was at the isloation valve at the boiler inlet..

When he also adjusted the mains stopcock to reduce incoming pressure the rise in pressure slowed down and vice versa !

what other causes can there be ??

 

[kevplumb]

the DHW h/ex is passing

 

[just-thinking]

there are a number of basic checks to be carried out first,before spending any money.
but needs knowledge and experience..priceless espically with your run of the mill mass produced boiler.
some of my neighbours and folk in pubs ask me to look at their boilers,i tell them i just do gas meter work.
espically when they mention 15 year old italy imports.
EX vokera engineer here..lovley boilers but need an expert to maintain them,they will last 30 years plus.[scush dont tell BG that]

 

[mmalone]

there are a number of basic checks to be carried out first,before spending any money.
but needs knowledge and experience..priceless espically with your run of the mill mass produced boiler.
some of my neighbours and folk in pubs ask me to look at their boilers,i tell them i just do gas meter work.
espically when they mention 15 year old italy imports.
EX vokera engineer here..lovley boilers but need an expert to maintain them,they will last 30 years plus.[scush dont tell BG that]

quite aware checks required mate, wasnt at the boiler myself, just asked about the symptons and to be honest the DHW HEAT EXCHANGER was suggested. Once he carried out the checks I suggested this was the best conclusion I could come to without actually being there to diagnose.

Cant think of anything else that would cause this either though !