Alpha boiler hot water problem

[mickboy]

There have been many posts on here about Alpha boilers and intermittant hot water.
I've been through most of these threads and followed the two main suggested cures.
I've replaced the diaphragm and the elecrical switch [temporarily with the suggest Maplins alternative. The reason I used the cheap alternative is because with this switch temporarily wired up the hot water still only works intermittantly When it does fire up press the microswitch and the heating goes of.
With the original micoswitch is place in the saddle the overall rate of working remains the same leading me to think the problem lies elsewhere
Any suggestions most gratefully received.

Cheers

 

[gas4you]

I assume you are talking about a 240/280?

If so, replace the primary thermistor. This can cause intermittent/hot/cold flow problems sometimes.

 

[mickboy]

I assume you are talking about a 240/280?

If so, replace the primary thermistor. This can cause intermittent/hot/cold flow problems sometimes.

It is a 240
Cheers for that I'll get one and let you know how I get on ,
Thanks again

 

[mrgas]

Are you sure its a 240?
These dont have the saddle/ horseshoe flowswitch.

 

[gas4you]

I assumed he meant the flow switch on the front of the diaphragm housing.

 

[mickboy]

Are you sure its a 240?
These dont have the saddle/ horseshoe flowswitch.

It's a CB 24 and believe me it definitely has the horseshow microswitch, I've bought and fitted it today {I'll not forget paying for that in a hurry}.

The hot water is still intermittant.
Now done diaphragm, microswitch and thermister Boiler same as before although my pockets much lighter, and depressions setting in.

 

[gas4you]

Now we know it's a CB24, try replacing the ch themistor.

 

[Paul Barker]

Are you sure its a 240?
These dont have the saddle/ horseshoe flowswitch.

It's a CB 24 and believe me it definitely has the horseshow microswitch, I've bought and fitted it today {I'll not forget paying for that in a hurry}.

The hot water is still intermittant.
Now done diaphragm, microswitch and thermister Boiler same as before although my pockets much lighter, and depressions setting in.

you've only got yourself to blame I would have fitted one part first time which would have fixed it were I the man stood infront of it. Don't be so suspicious of paying a trained professional.

 

[mickboy]

Now we know it's a CB24, try replacing the ch themistor.

Pau I' ve just followed advice given on here to previos posters in the order the advice was given
Sorry to be a pest but I've been off work today and had a play around the boiler.
H/w does not always come immediately. and goes on and off as previously stated and then sometimes doesn't come back on 'till it feels like it .
What I've noticed today is that with the cover off You know if the h/w is going to fire because you can clearly hear the horseshoe switch operate. If you cant hear that no h/w. But come but to it later you may or may not hear the switch operate and if you can hear it, hot water, again all be it intermittantly.
As you know Ive replaced the diaphragm but does the switch not operating each time the water is turned on mean a new divertor's is needed.

 

[mrgas]

Mick,
You can not hear the microswitch working.
Like Paul says If I had been in front of the boiler it would now be fixed.
To get good advice from us we need to know which boiler you have.
And the exact nature of the problem.
A 240 is not a cb24. They may both be alphas but everything else is different.
Intermittant hot water has many causes and meanings.
If you change all the thermistors the plate heat exchanger the diverter valve the flow switch the pump and fan and for good measure the pcb and do them all correctly it may work.
Or get a good engineer in!
There are many about!
We are not all rip off cowboys!

 

[Paul Barker]

Actually mrgas though you are in the same frame of mind in this as me, and you are like Chris and Agile in not being able to hear the click. I can hear the click on an Alpha.

My test procedure is to listen for the click no click and no hot water = diaphragm or a bit of debris holding the diaphragm from making sufficient suction to move the pushrod. Click and no hot water usually = microswitch, but this fault is very intermitent at first to test a horseshoe microswitch have to run hot tap at least 20 times in a row. A failing one will just fail 1:20 at first. But any failure at all even if 1 : 100 change it.

Over time various thermisteres have been tried in Alphas Black are not bad, white are absolutely bullet proof, they were just starting trials on orange ones when I finished working for them so don't know how they turned out, blue like the vokera ones are a pile of pooh red are for danger. pcb's bullet proof, never used a cb pcb used a few cd ones also never used 240/280 pcb. Fans last forever aps's almost as good as the fans but they do fail.

But for the op what we are both trying to say is that there is more to fixing a boiler than we can convey to you here. At the end of the day we gained our diagnostic and testing to prove part required skills over years in front of a whole range of boilers. We cannot give you that experience in a text only discourse. When we stand in front of your boiler it will more than likely stand out to us like a saw thumb where the problem is. to get that you have to pay one of us types to come and stand there, keep quiet and let us use our senses on the boiler undistracted and you will get good value for money.

 

[mickboy]

Appreciate all your time and info , Im off on holiday now so I'll get it sorted when I get back, by which time my mate who fitted it should have returned from his stay in Dubai.
Thanks again.