Baxi 105 combi hot water problem

[slamdunk]

Hi
I've got a Baxi 105 Combi boiler about 2 years old. Recently it has developed a fault whereby the hot water aspect of the boilers operation does not start when a hot tap is turned on. If a second tap is turned on, then the water is heated as normal. The boiler continues to heat the water after the second hot tap is turned off.

I suspect the fault is with a flow or pressure switch within the boiler, a single tap does not provide enough flow/pressure drop to close the switch, whereas two taps will. Once closed there is enough flow from one open tap to prevent the switch from opening again until the tap is shut off.

I have no idea how to go about repairing this fault, or indeed identifying which component is faulty, I'd get a plumber, but despite several promises one has yet to arrive at our door!

Can anyone help me out please?

 

[Baxi-Remeha]

presure diff 'sticking'. do you live in a hard water area????

 

[DP]

Boiler should be serviced (proper service) annually. That should take care of the boiler

 

[B.O.B DOLE]

Boiler should be serviced (proper service) annually. That should take care of the boiler

i thought this would be treated as a breakdown
fixing this would not be part of a service

 

[ChrisR]

Sounds like a "normal" 105 faulty diaphragm/diverter valve to me, not the pressure switch.
You sure you read it right Jason?

 

[slamdunk]

yes, the water is fairly hard in this area.
If it's the diverter, is it a DIY job to fix, or is the level of skill required too great, should I get a plumber?
If it's a DIY job, then any tips???? Please!

 

[slamdunk]

Oh, and how much should it cost if I can get a plumber to do the work, including parts?

 

[ChrisR]

Yes it's the sort of thing you could do yourself if you take your time.

If you change the diaphragm and centre gland seal (which tends to leak) You'll probably fix it. But if the old diaphragm isn't holed you'll know it's something else!

Instructionsetc are on partsarena/baxi. Diaphragm is under £10, can't find a number for the seal..

 

[Baxi-Remeha]

chrisr - ditto........i didnt mention a switch........ the pressure diff is the big brass round thing with the 'switch' stuck to the front...... dose sound like its sticking, probably due to a leak.

 

[ChrisR]

Yes I know where the tap water flow switch is! I disagree that it's llikely to be stuck. If the diaphragm is OK the centre shaft would move full travel with one tap open. So the switch wouldn't know the difference.

 

[Baxi-Remeha]

read it again........... didnt mean switch sticking, ment pin sticking.....

 

[Charlie Shields]

Just had this problem remedied. It was exactly as you described. The rubber diaphragm had worn and was leaking. I had it replaced by a plumber at a total cost of £60. Boiler as good as new now.

 

[DP]

When I said service should take care of it, I meant exactly that. It is my experience that many a defect is directly related to lack service as indicated in MI.

 

[slamdunk]

Thanks guys, your help was invaluable, turns out my boiler is actually an instant 105e (what's in a name), and even easier to fix than the other, cost me a grand total of a tenner and about twenty minutes work to do the job, and now I have hot water on demand. I must admit that on reflection £60 seems a bit of a hard pill to swallow for such a quick fix.
Once again many thanks

 

[DP]

20 minutes on site does not equate to 20 minutes for the total job.

Someone charging £10.00 to carry out a task will certainly not be paying for the part (as mentioned earlier the diaphragm itself is £10). I fail to see how ANYONE can travel to the suppliers, buy the spare, travel to the client's house, carry out the repair for £10 will be able to show a profit AS WELL as pay for the overheads.

All I can say is you have won a watch (gold at that)