alpha ocean combi hot water problem - resolved!

[Bygravey]

Guys

have a alpha Ocean combi about 4 yrs old. Pressure is Ok but the hot water only works when the heating is on. When no heating no hot water. Could it be a diaphram or soemthing?

Any help much appreciated.

Thanks

 

[ChrisR]

Plenty here - do a search on CB24 and you should find out about the diaphragm, clip on switch, sticky diverter, dodgy sensors..

 

[Bygravey]

Thanks Chris
In terms of sequential steps when diagnosing the problem what would you do and how? (can't find any info on the web)
Thanks

 

[Rob]

I may be wrong but the alpha ocean is similar to the performa.

The flow switch is a round 3'' brass thing to the left, you need to see what the spindle does when a hot tap is run.

 

[ChrisR]

If it's not a CB series it's older than that, like a 240.
Same principle - search on the model number, it's a common question.

Unless it's an Ocean Style FF - in which case just bin it!

 

[Bygravey]

It is a CB

 

[gas4you]

Diaphragm housing to the right, next to/behind pump. Check flow switch that is clipped on top of pipe to left of diaphragm housing.

 

[Bygravey]

Have resolved and cannot believe how quickly on a Sunday! My old man is a plumber and gave him a buzz and he confirmed pretty much what is said here and other posts within this forum. Lots of similar hot water problems with the CB24/28. He recommended changing the micro switch (he had one to hand) cost £24. He fits lots of Alphas and reckoned about 7/10 it is the micro switch. So did this in less than 10 mins was resolved. So for the purpose of the this board I think that's a good first stab and as Paul (given lots of advice to this problem on other posts) says worth changing anyway as good practise. One relived man. thanks to all submitters!

 

[Paul Barker]

Shut the isolator at the right hand side underneath towards the back, don't worry it isn't likely to leak afterwards they are very reliable. Now does water get hot?

Diverter valve needs reconditioning. we just change this section, I am not supplied with a primary side service kit but the might be available phone 01732 783001 and ask Mike if there is a service kit for the primar side. There is one for the hot water side but sounds to me like you need the primary.

The microswitch which latches onto the neck of the DV can be fault but that is eas to test. Run the tap repeatedly whilst listening, does the switch click? The diaphragm is OK> Does the boiler light? the switch is OK.

When microswitch first goes fault customer reports no hot water just two or three times a week, so to actuall catch it doing it ou might have to operate a tap 20 times or even more, as soon as it fails even once, you have your diagnosis.

Next sound after the click should be fan start then stop then start again, soon as ou hear fan start you can go back to beginning and test again, repeat and repeat until it fails.

 

[Paul Barker]

Now I see you posted solution while I was typing.

We are told that the new microswitches we are fitting now are better.

Like any boiler with one, the diaphragm is going to need changing sooner or later.

9 X out of 10 switch is the problem, but when a plumber phoned alpha to sa the boiler needed a new DV, in warranty period the said we'd rather send our man. On phone we all agreed it wouldn't be the DV. When I got there, knock me down with a feather I had to change the DV.

 

[Bygravey]

Good stuff - thanx Paul!