Baxi 105e - Heating but no hot water

[harpercr]

Good morning all,

wonder if anyone can help with a problem with my Baxi 105e boiler.

Had no hot water this morning, but the heating works fine - even with heating on, get no hot water. Held left dial in reset position for 10-20 secs but to no avail.

No warning lights are on - I am correct in thinking that the top row of lights will indicate what the fault is?

Pressure is just over 0 - so suspect that's the issue - but wouldn't that affect the heating? Any advice greatly appreciated!

Thanks,

Craig

 

[Agile]

Would you drive a car with flat tyres?

First pressurise to about 1.5 Bar and see what it does then!

 

[harpercr]

Thanks for the reply fella - daft question and I'm just curious why this wouldn't affect the heating then?

Increasing the pressure is the same as re-pressurising then - and fairly straightforward?

 

[harpercr]

Have looked into the process to re-pressure and it says about adjusting both ends of the silver pipe to increase the pressure.

Trying to get my head around exactly how this increases the pressure - could someone point me in the right direction?

Thanks a lot.

 

[Egga]

There will be a flexible silver pipe with 1 or 2 handles on it.
One side is connected to the mains water, the other to the heating circuit.
You need to open the handles until the pressure gauge needle reaches 1 bar.
Turn off the handles.
Switch boiler on and see what happens.

 

[harpercr]

Thank you so much for your help - we have hot water. Thanks for saving me a call out fee for a 1 minute job!!

Just confused why the heating still worked - is that not as dependant on pressure as the hot water?

Thanks again.

 

[harpercr]

Strange update......after re-pressurising last night we had hot water - didn't run a bath or anything but seemed to be running hot enough for a while.

Woke up this morning and we didn't have any hot water again, then managed to get enough to fill half a basin before it went cold again, and now its cold again. Dial for water is set to 9'o clock - so guess it should be preheating.

Again no warning lights, but heating working fine. Pressure fluctuates between 1 and 2 - should it fluctuate this much in the space of 20 minutes?

Any ideas anyone - much appreciated?

 

[ianmcd]

Most likely that your domestic hot water diaphragm needs replaced, very easy job on this boiler and not expensive

PS this boiler does not have a Hot water pre-heat function that you mentioned

 

[harpercr]

Thanks for the reply. When you say very easy - does it need to be done by a gas engineer or a simple diy job?

Thanks

 

[ianmcd]

no its not inside the combustion chamber so you could do it yourself make sure you isolate the electricity supply before starting and turn off the cold water supply to the boiler and open a hot tap to release the pressure and the tap will stop running a small amount of water will come out when you split the diaphragm housing so be sure to place a towel or something under it to protect the electronics

 

[45yearsagasman]

This may help View media item 31064

 

[harpercr]

Just tried to get a part and spoke to a very helpful guy at the local shop.

He's advised that where the pressure fluctuates between 1 and 2bar that the pressure release valve needs re-pressurising first, and it can be done with a bike pump to about 7psi, but have to use the drain tap first to release the pressure.

Does that make sense?

Thanks as ever to you all for the very helpful advice!

 

[Egga]

Is it a 105e or a 105e instant? You say it has preheat.

the dhw diaphragm iare different in these.

Make sure you get the correct one.

 

[harpercr]

Just checked and its a Baxi Combi Instant 105E

Untitled

• harpercr
• 11 Dec 2012
• 1

So does it make sense about repressurising the pressure release valve before swapping the diaphragm?

 

[ianmcd]

well would have helped if you had told us the correct model in the first place, but its still the DHW diaphraghm that needs replacing and what the guy in the shop told you is probably correct but you have it completely mixed up, the pressure going from 1 Bar to 2 Bar when heating is on is a completely different fault and nothing to do with your Hot water