Biasi 24s combi, not calling for hot water.

dave123456_2

My Biasi 24s recently stopped working. The central heating side is fine, and works ok, whereas the hot water side has died.
When turning the hot tap on, nothing happens...just cold water, i have turned off the power for a while, in hope that it may reset itself....no joy.
Is there a pcb that can be replaced to sort this out or maybe even a simple part.

Cheers in advanced.

weekendwarrior

I'm not an expert, but it could be the diaphgram.

dave123456_2

where would this diaphragm be located??????

weekendwarrior

it'll be in the diverter valve I think, like I say I am no expert.

plumb1_2

diaphragm split in the diverter valve on the left hand side,needs replacing.

Or it could be the DWH temp sensor

gasmanmartin

more than likely it's the diaphram. if you take off the boiler casing you will see a round disk shape with screws all round the outside. infront of this is a switch, every time you turn on a hot tap the differential pressure pushes the diaphram forward and moves a pin (which makes the switch) If you are feeling brave you could take the switch off and push with a pin (while hot tap running) and if you get hw then thats your problem. Your manufacturers instructions will tell you exactly what to do. if in doubt contact a heating engineer. This is the most common fault on a combi, there is a chance it may be something else but this is the best bet!

dave123456_2

ok, thanks all for that, i have had a quick look and located the diverter valve, what i need to know is whats inside....is it full of water?????, basically if im going try the solutions in the last post, what is my plan of action.

Cheers.

plumb1_2

Turn off your mains stopcock and open all your hot water taps to drain the hot water side of the boiler...leave them open until you refill. There are 2 circlips on this one holding two small tubes...you need to take the circlips off and remove the tubes, probably get a bit of water flow from the taps now and a bit of a dribble from the pipes. Now you can undo 2 small grub screws on the valve body behind the diaphragm housing and pull the housing off. When you've got it in your hands you can unscrew all the screws and replace the diaphragm. Just reverse it all to put it back. The only time you will need to drain your heating side is if the valve has been passing, but then the whole valves requires replacing anyway.


copied/pasted

dave123456_2

ok, so i stripped down the diverter and found a very small tear in the crease of the diaphragm, i hope this is the problem, now i need to ask, if anyone can recommend a good online store that can supply me with a diaphragm kit and quickly.

gasmanmartin

your best bet is probably a local plumbers merchants (plumbcentre,plumbline) as they will have these in stock and you can get it there and then - no need to wait on post. take along the old one and make sure you get the right one

Rich-T_3

For everyone involved in this post, thankyou so much! I had the same problem and managed to fix it myself because of this post. It saved me a ton of money I couldn't afford to spend just at this minute- lost my job in the 'downturn'. Thankyou you to everyone who knows something useful and is willing to give up their time for others! Cheers!