Baxi 105 E Instant

[cristoforo]

Guys im giving this one last go My Baxi 105e Instant pressure gauge is going off the clock when the CH is on and venting out through the prv there is 1 bar in the expansion vessel and the plate heat exchanger is not passing water and the filling loop is disconected. guys please what else could it be that is making the pressure rise so much? im at the end of my tether and fed up of spending money on it. am i missing something simple ? Cris

 

[gigz]

Are your rads warming up underneath the boiler make sure the CH valves are fully open. Turn the cold inlet valve off under the boiler and turn CH on, what happens now

 

[cristoforo]

hi rads are getting hot and flow and return valves are fully open i will turn the cold valve off tonight and try that. whats your thinking with that one?

 

[gigz]

Just in case water is mixing somewhere inside the boiler (uncommon but not impossible)

 

[cristoforo]

Thanks Gigz could it be the water store that is connect to the expansion vessel ?. Only trouble is there is no water in the expansion vessel so the diaphram is still intact

 

[gigz]

Would'nt think so, if your filling loop is disconected the only way your pressure guage would go up is by a short curcuit inside the boiler, and i thought maybe the CH valves were closed as this would make the CH water expand and boil

 

[DP]

What difference will close iso valves make to boiler pressure? While it is not the done thing, I cannot understand how boiler pressure will rise from 1 to 3 bar, just because the isolating valves are closed.

Suspect faulty expansion vessel.

 

[cristoforo]

I have thought it was the expansion vessel from day one its just that there is no water in there and the fact that when cold and system drained the vessel still has 1 bar in it. ill order new expansion vessel and see how that goes mabye its just not working properly Thanks guys

 

[fitz1]

try and clean the pipe out that leads to the ex vessel.

 

[Rob]

try and clean the pipe out that leads to the ex vessel.

99% that it wil be this

 

[scatmanjohn]

try and clean the pipe out that leads to the ex vessel.

99% that it wil be this

I doubt it on this model as it uses the exp vess as a heat store for the instant hot water feature.


Is the instant feature turned on and working.

 

[gigz]

What difference will close iso valves make to boiler pressure? While it is not the done thing, I cannot understand how boiler pressure will rise from 1 to 3 bar, just because the isolating valves are closed.

because if iso valves are closed pressure would build up as heat would not be dispersed

 

[cristoforo]

try and clean the pipe out that leads to the ex vessel.

99% that it wil be this

I doubt it on this model as it uses the exp vess as a heat store for the instant hot water feature.


Is the instant feature turned on and working.

yeah pre heat is on and working fine i only have a problem when the CH is switched on and the pressure goes around to 3 bar then when it then goes cold the pressure gauge goes down to 0. When drawing hot water the preesure is fine

 

[Rob]

try and clean the pipe out that leads to the ex vessel.

99% that it wil be this

I doubt it on this model as it uses the exp vess as a heat store for the instant hot water feature.


Is the instant feature turned on and working.

i withdraw my statement

 

[ChrisR]

i withdraw my statement

Not so hasty perhaps, could be something around that. It's a flow-through thing isn't it, with check valves presumably. If something was stuck or blocked....?
Would need chin-scratching!