my alpha cb 28 is playing up for the second time , it wont deliver hot water and CH the B light is flashing saying that it could be the temperature sensor faulty , last night it came on temporarily for about 20 minutes and then overheated and the A red light came on , i reset it to no avail .... has anyone had similar problems ........
Alpha CB28 no hot water or central heating
- Thread starter pauld115
- Start date
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It does sound typical of a sensor fault.
To reply to your stupid question, yes, lots of people have had similar problems. They keep me occupied fixing boilers!
Are you completely happy now that you know that you are not alone in having a faulty boiler?
Tony
To reply to your stupid question, yes, lots of people have had similar problems. They keep me occupied fixing boilers!
Are you completely happy now that you know that you are not alone in having a faulty boiler?
Tony
Your problem may not be a CH problem, or most likely isn't a CH problem. Once the boiler has locked out during hot water use, the CH won't work until you reset it.
You have to be a lot more thorough before we can even begin to help you.
But with what I know about the boiler in general and the little I have learned from you, I will be a prophet.
It is sludge in your plate heat exchanger!
You have to be a lot more thorough before we can even begin to help you.
But with what I know about the boiler in general and the little I have learned from you, I will be a prophet.
It is sludge in your plate heat exchanger!
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had british gas come along , he diagnosed that the pcb needs replacing so he did , then he changed two sensors overheat and another one . got it up working for an hour after he left then the red light came on and locked out again !!!! would you believe it ?? so back to square one in having to reset it when it locks out !!!
I don't remember Tony but the ntc's are bullet proof they were never ever the fault when I was fixing them. Faults like this on an alpha cb range were always the plate to plate sludged up.
The pcb is bullet proof I never needed to fit one. Typical of a numpty to change that first.
The things to check are plate heat exchanger and pump. Buyt most likely the plate. Also would have set properly the burner pressure which the numpty that goes round changing pcb's probably didn't even check.
I do realise that unfamiliar boilers you are looking first at the temperature sensor, it's just that I do know how hardy the ntc's are on this boiler, not just my experience I said to the senior engineer how I had never needed one he said "no you won't". The best ones are white coloured they were trying out some orange dry pocket ones when I left no idea how they worked out, black were before white they were on the whole good aswell, but before that they tried blue and red both of which were as unreliable as vokeras and the red was the worst.
I am assuming op's boiler is more recent and has the white ones in. I would be amaised if they need changing.
As for changing an alpha cb pcb. The bloke clearly has no alpha experience worth a light.
Thank you for the great advice, i thought something was wrong with the engineer when he said to me that British Gas had put him on a 12 month course and was fully qualified! well seeing as he has giving me about £500 worth of new parts for nothing i suppose its a good deal but back to the problem of sludgy plate would you recommend a private power slush or should i get British Gas to do it !
Bear in mind I am only talking experience and hunches, to diagnose I have to be in front of the boiler.
If the plate heat exchanger is the problem, which is not definate, but likely, then it can be fixed without a powerflush.
I used to find that on systems which had had a good powerflush which I know was done well, plate heat exchangers get sludged up. It is their nature.
The BG powerflush is good value because they then own any sludge problems in your boiler as long as you stay on contract. For that reason alone I would recommend you stany with bg and have them powerflush it.
BUT Alpha offer a maintenance contract on the boiler. If you had been in my area I would have fixed your boiler on that contract even if it were due to sludge in the system. But I cannot speak for others.
an Alpha engineer will not waste visits or time fitting the wrong part, he will generally get it right fist time and fit one part if at all, and properly check the set up of the boiler.
If the plate heat exchanger is the problem, which is not definate, but likely, then it can be fixed without a powerflush.
I used to find that on systems which had had a good powerflush which I know was done well, plate heat exchangers get sludged up. It is their nature.
The BG powerflush is good value because they then own any sludge problems in your boiler as long as you stay on contract. For that reason alone I would recommend you stany with bg and have them powerflush it.
BUT Alpha offer a maintenance contract on the boiler. If you had been in my area I would have fixed your boiler on that contract even if it were due to sludge in the system. But I cannot speak for others.
an Alpha engineer will not waste visits or time fitting the wrong part, he will generally get it right fist time and fit one part if at all, and properly check the set up of the boiler.
It's not a toss up in my mind.
Alpha are 100 times better to look after an Alpha boiler.
Bg look after the whole system.
You seem to be fixated on the idea of a powerflush.
It may not be required. bg engineers have to try and sell you a heating upgrade it's one of the things they are monitored on at their revfiew and in many cases they are asked every day how many upgrades how many co detectors and how many sales leeds they have achieved.
Your fixation is further supported by the number of sheep who bleet on here powerflush powerflush powerflush!
Have I said you need a powerflush? Ask the bg engineer to do a termidity test look at the water in the clear vessel, can you see two rings in the bottom from the top? your water is not that bad!
As I said plate heat exchangers are designed to catch sludge. Yours has done good service, get it cleaned or renewed, a normal system water cleanse might be called for.
Save some money.
I have successfully cleaned plate heat exchangers completely blocked which caused the overheat trip you are experiencing and restored full hot water performance in 1hr's labour and one bottle of strong chemical. I haven't yet failed to get a satisfactory result.
Alpha are 100 times better to look after an Alpha boiler.
Bg look after the whole system.
You seem to be fixated on the idea of a powerflush.
It may not be required. bg engineers have to try and sell you a heating upgrade it's one of the things they are monitored on at their revfiew and in many cases they are asked every day how many upgrades how many co detectors and how many sales leeds they have achieved.
Your fixation is further supported by the number of sheep who bleet on here powerflush powerflush powerflush!
Have I said you need a powerflush? Ask the bg engineer to do a termidity test look at the water in the clear vessel, can you see two rings in the bottom from the top? your water is not that bad!
As I said plate heat exchangers are designed to catch sludge. Yours has done good service, get it cleaned or renewed, a normal system water cleanse might be called for.
Save some money.
I have successfully cleaned plate heat exchangers completely blocked which caused the overheat trip you are experiencing and restored full hot water performance in 1hr's labour and one bottle of strong chemical. I haven't yet failed to get a satisfactory result.
i took your advice and got Alpha out today who went straight to the problem , "Air pressure switch faulty" he replaced it and now working fine, i should have done that in the first place , countless call outs by BG who could nt find the problem , but they did give me a new PCB board two sensors and a thorough check up and clean. thanks for thev advice
I have never needed a pcb for that boiler. Have hardly ever fitted a fan but have fitted a couple of aps's loads of flow swictches and quite a few diaphragms. Cleaned loads of calorifiers, I don't think they use a very good one, as the systems it sludged up on were really quite clean.
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