Alpha 240E problem

[Gmanhitch]

All, first post and looking for a bit of advice, have read a few other older topics relating to this boiler but none quite cover my issue.

Basically for the past 8 weeks UU have been digging up my street replacing water pipes, while they were doing this the water pressure dropped and as a result sometimes we had to turn the hot water tap on full to get the boiler to kick in for the hot water. I thought the issue would clear up.

However they finished a week ago and for the past three days the hot water on the boiler has given up the ghost.

Basically, the boiler does not seem to sense when the hot water tap is turned on, i.e. no light on the front comes on, but no warning lights flash either.

Hot water works fine when we switch on the central heating, but clearly middle of summer and would like to get sorted.

Have read other topics relating to DHW flow switches and valves, and diaphragms on other posts but as I am no expert, wanted to check if mine is likely to be a similar issue.

Unless something very simple will be getting someone to come in, but before i do would like to have a bit of info about what the problem maybe so i don't get the wool pulled over my eyes.

Bought house 5 years ago and no manuals or anything left, circuit board replaced 18 months ago, but the whole thing died then.

Any help appreciated.

G

 

[waterworks]

Drop down front flap turn on tap and watch for front pin to come out and push on the micro switch, if pin doesn't come out then the hot water diaphragm has gone if pin comes out then the micro switch probably needs replacing, you can change it over for the main flow micro switch which is on the top of the diverter valve as a check turn off electrics first though.

 

[Gmanhitch]

Have just done what you said, not sure if good or bad news.

Pin seems to come part way out, not far enough to push the mircoswitch.

When I manually flip, hot water comes on, so I guess its not the mircoswitch, is this therefore a problem with the pin sticking, or a diaphragm problem.

If so is it easy to replace the diaphragm as a DIY'r, bearing in mind I don't have manual etc, how much is the part?

 

[waterworks]

Fairly easy job if you are up on diy jobs.
Turn off domestic water supply to boiler open hot water tap, remove micro switch remove top front small pipe undo all the screws arond diaphragm housing be prepared for it to jump forward as it has a spring behind it, replace diaphagm bought as a kit ie rubber diaphragm, front seal and silicone grease.

YOU don't have to turn off or drain heating side of boiler.

 

[Gmanhitch]

Waterworks your a star.

Just so i get this right, isolate water supply at stop cock, no need to drain, by far my biggest concern.

Turn on hot water to drain water supply from hot water.

Access diaphragm housing, which I think from research is in the second vertical chamber behind the horizontal chamber that the pin we have discussed about pops out of.

Replace seal and fingers crossed.

P.S. Any recommendations for getting a replacement diahpragm? Probably have a crack over the weekend.

 

[waterworks]

Isolate water at in coming main supply to boiler screw slot balafix valve under boiler 15mm pipe second pipe in from right i think, open a hot water tap to relieve pressure.
Housing is the large round brass fitting on the right which the micro switch is mounted on which has screws all around it.
You will get a small amount of water out when you undo screws so place a container under it.

 

[waterworks]

Correction large round husing on the left as you look at boiler

Sorry don't know my left from my right

 

[gas4you]

Buy the Baxi 105 diaphragm. It is about 1/3rd the price of the Alpha and is the same part.