Confirmation needed!

[martinhurley]

Hey all. im a plumbing and heating engineer that mainly deals with installs but my mother in-laws boiler is playing up. the heating is constantly on even tho the room stat is not calling for heat. i have come to the conclusion that its the diverter valve sticking as when i tap the valve it shuts off. then when its on hw only and the hot tap goes on the heating will go on aswell and not shut off, so could this be the micro switch also?
its a baxi 80 eco.

 

[GasmanxxxR1]

Had the same problem in my own house

The actuator of the three way valve was sticking and providing a live to the boiler. I had a drayton valve with removable head so i took it off and played around with the actuator arm, freed it up and now its ok.

You can try this or you might need to replace it

ps im an installer too!!!!!

 

[Billy Bob Bob]

stuck diverter more than likely when it runs to ch is the ch demand light on?

 

[martinhurley]

yeah the demand light is on gas man. will i need to replace it or can it be fixed?

 

[Billy Bob Bob]

yeah the demand light is on gas man. will i need to replace it or can it be fixed?

in that case its not your diverter this is defo a 80 eco not a instant?

 

[martinhurley]

gasmanxxr1 ur problem sounded like its on a system, this is a combi. thanks for the reply tho!

 

[martinhurley]

its a combi gasman

 

[Billy Bob Bob]

its a combi gasman

i know:smile5: but there are 2 versions the 80 eco and 80 eco instant they look the same from the outside the one your looking at does it have the large round brass diverter?

 

[martinhurley]

oh ok this it what it looks like

 

[Billy Bob Bob]

its a 80 eco,if that had jammed you would get ch in dhw mode BUT not the ch demand light on,for the light to be on it needs a electrical signal any leaks near the ntc or from the main heat exchanger? you could also have a sticking flow switch

 

[martinhurley]

its a 80 eco,if that had jammed you would get ch in dhw mode BUT not the ch demand light on,for the light to be on it needs a electrical signal any leaks near the ntc or from the main heat exchanger? you could also have a sticking flow switch

yeah thats what i was thinking about the demand light being on. there is no leaks now but a few months ago there was a leak on that front, little nut where the plunger rod is (fixed now tho) the flow switch doesnt seem to stick, when ive tapped the valve and the ch plunger goes down the switch can be pressed and you here the click.

 

[Billy Bob Bob]

take the pcb out and dry it check there is no water in the houseing

 

[martinhurley]

its been a while since the leak. i had the cover off today and never noticed any water or dampness!

 

[Billy Bob Bob]

i would be looking at a pcb fault personally ,give baxi tech a bell see if they confirm it

 

[martinhurley]

ok gasman i will do that. thanks for your time i really appreciate it

 

[Billy Bob Bob]

come back if baxi cant help

 

[martinhurley]

hey gasman. i got it sorted. i took another look yesturday evening and noticed the micro switch on the dhw side wasn't de-pressing. it was constantly on hence the constant demand for heat. swapped it over this morning. thanks again for your help.