Baxi combi boiler no hot water help!?

Sam077

Hi all,
First Post so I'm sorry if it's in the wrong place!
I have a Baxi combi 105e which has lost pressure yesterday, I still have heating but no hot water
I have tried repressurising the boiler whilst turned off but no water is flowing through the valves, I am only able to hear water flowing if I open the valves whilst the heating is on.
Does anybody have any ideas please?!
Thanks in advance

pattypan4

Check for air in the rads first, let it out. Then move the lever in the boiler to bring the dial pressure up to about 1.3, water will move, you will hear it and pressure will build. . Check also the diverter, it will move one way for hot water and the other way for ch. Hot water will have priority. It might have stuck, so move it by hand, hot water should flow. Diverters do break down btw. Diverter is a small box like device on the pipework somewhere, mine is away from the boiler
Not to alarm you but sudden pressure loss could be a leak somewhere in the system.

jefaz07

Could be a hot water diaphragm split in the pressure differential. The pin won’t come out and make the microswitch.
But also low pressure won’t make flow switches but you say you have heating?
Are you opening both levers on the fill loop? (If it has 2)
And you are opening the correct valves.
And with no hot water do you mean there is water there but cold? Or no water at the taps...I’ve seen people think they are opening the full loop and actually isolate the cold inlet.

jefaz07

pattypan4 wrote: »

Check for air in the rads first, let it out. Then move the lever in the boiler to bring the dial pressure up to about 1.3, water will move, you will hear it and pressure will build. . Check also the diverter, it will move one way for hot water and the other way for ch. Hot water will have priority. It might have stuck, so move it by hand, hot water should flow. Diverters do break down btw. Diverter is a small box like device on the pipework somewhere, mine is away from the boiler
Not to alarm you but sudden pressure loss could be a leak somewhere in the system.

By diverter I assume you mean a zone or mid position valve? Not at all relevant here.

Sam077

Should bleeding the rads help? Should this then allow me to top up the preasure as this is something I am unable to seem to do? Thanks in advance

Sam077

Hi yes I have heating and am opening both valves in the correct order on the filling loop

I have cold water, if the heating is on the hot water may run for around 3 seconds and then shoot back down to cold, if the heating is not on the cold water will always be cold
Thanks in advance

jefaz07

Then I’m going to suggest the diaphragm. It’s common. I’ve changed 100’s, literally. Only about £12 for the part.
When you put the tap on does the ‘tap’ icon illuminate on the front of the boiler?

pattypan4

Maintenance costs should be in your annual calculations. Get a bona fide heating engineer in. My last boiler service and check was only £75.

jefaz07

pattypan4 wrote: »

Maintenance costs should be in your annual calculations. Get a bona fide heating engineer in. My last boiler service and check was only £75.

A service would never pick up on this issue if it’s the diaphragm. Nor would it solve the issue.
The amount of people who ask for a service when there is a fault is staggering. A service won’t fix a fault.

pattypan4

My plumber tested my system thoroughly and he would definitely have picked up a fault. It was more than a routine service. I have the boiler serviced and tested every year, like a car service, routine in my diary

Sam077

Hi yes tap icon illuminates and preasure does go up but water remains cold