Alpha CB24 Flashing Indicator Neons, No Hot Water/Heating, please help?

[dave1066]

On Sunday I discovered my Alpha CB24 had no power. On inspection, the main terminal fuse had blown. With a bit of trial and error I found that disconnecting the fan from the circuit board and replacing the fuse powered the boiler back up. So I replaced the fan Monday. Everything worked fine for a night and day, then on Tuesday evening done the dishes and we had hot water. Then 10 mins later go to run my daughters bath and theres no hot water. When you turn on the heating or run a hot tap the boiler makes a noise like its trying to do something and then the yellow and red indicator neons start flashing together.
Please can anybody help?
Thanks

 

[diamondgas]

:welcome: to the forum dave1066 🙂 What's your background? Disconnecting the fan alas does little except disrupt the lighting up sequence IMO

 

[dave1066]

Hello, thanks for your welcome and reply.
Backround, I am studying to be an automotive engineer and a dab hand at most things DIY. Just trying to see if the boiler is fixable myself before I call in the pro's.
I would also add that the new fan isn't spinning. Any ideas what it could be?
Reading around sounds like people are saying new PCB, but im just hoping it's not as they are not cheap.

 

[Alpha man]

A-B flashing together, could be either the PCB (no power to fan) or the fan itself, My money would be on the PCB!!

 

[dave1066]

I was afraid you might say that :sweatdrop:
How much is a new PCB do you know? Is it just a case of swapping the board over or does it need to be programmed aswell? How long should it take to fit a new one?

 

[dave1066]

Only asking as British Gas quoted £199 for a 1-2 hour job inclusive of any parts. Which sounds like a good deal if a PCB alone is £150. But if the job takes longer than 2 hours then it's £419 which I can't afford.

 

[Alpha man]

20 mins to fault find and fit, and its a simple plug and play PCB.

 

[diamondgas]

Only asking as British Gas quoted £199 for a 1-2 hour job inclusive of any parts. Which sounds like a good deal if a PCB alone is £150. But if the job takes longer than 2 hours then it's £419 which I can't afford.

Get a local guy or post a requests here dave [DLMURL="http://www.ukplumbersforums.co.uk/im-looking-plumber-gas-engineer/"]I'm looking for a Plumber or Gas engineer.[/DLMURL]

 

[dave1066]

Thanks for the info Alpha Man.

Diamondgas - Im all for using self-employed/small businesses over corporates. I am self-employed myself and have many friends/family who are local tradesman but sadly none of them Gas Engineers.
However I dont think a local guy would benefit from taking on my job? As I was thinking of returning the new fan I bought (£114) calling out British Gas for there all inclusive £199 deal to get both the fan and pcb replaced. The jobs probably going to cost them more in parts.

 

[diamondgas]

Record the time they're their Dave, should you choose BG even get the guy to sign an agreement time arrived and left! .. Although you shouldn't have to as they're timed to the minute via their computers 🙂

 

[dave1066]

Good idea, thanks for the advice
All depends on if I can return the fan tomorrow morn. If I do call BG out should I leave the boiler with the casings off so it saves them time or should I put it all back together and pretend i've not touched it? :wink_smile:

 

[diamondgas]

Good idea, thanks for the advice
All depends on if I can return the fan tomorrow morn. If I do call BG out should I leave the boiler with the casings off so it saves them time or should I put it all back together and pretend i've not touched it? :wink_smile:

Be honest wiith the guy and it'll shorten their time Dave ... I've wasted loads of time beating about the bush only to find out that the customer has tried/tested but afraid I'd say something ... Your input reduces the time spend getting to the bottom of a fault ..... We can discern 🙂

 

[dave1066]

Yeh your right. I will keep the casing off and explain what ive tried. Thanks for all your advice.

 

[dave1066]

Well I managed to return the new fan and get a refund.
I phone BG and arrange a visit and tell them to bring a fan and PCB when they come round.
BG engineer has been to diagnose, didn't bring any parts and puts the fault down to being the fan. Regardless of me telling him I have fitted a new fan and there is another fault. He can't get parts till tomorrow.
He then goes on to tell me that the all inclusive parts quote only covers the fan and I will be charged further for more parts if needed.
So it's gonna cost £199 for him to come back tomorrow, fit a new fan maybe check the air pressure switch but if that doesnt work gonna cost more.
I'm not sure what to do? Cancel BG and fit a new PCB today myself and hope that fixes it or see what happens tomorrow?

 

[dave1066]

Too impatient...I repaced the fan and PCB myself, all fixed. Yay.

 

[diamondgas]

Too impatient...I repaced the fan and PCB myself, all fixed. Yay.

Good to know you've got it up and running again Dave .... 🙂

 

[eccoboy1974]

On Sunday I discovered my Alpha CB24 had no power. On inspection, the main terminal fuse had blown. With a bit of trial and error I found that disconnecting the fan from the circuit board and replacing the fuse powered the boiler back up. So I replaced the fan Monday. Everything worked fine for a night and day, then on Tuesday evening done the dishes and we had hot water. Then 10 mins later go to run my daughters bath and theres no hot water. When you turn on the heating or run a hot tap the boiler makes a noise like its trying to do something and then the yellow and red indicator neons start flashing together.
Please can anybody help?
Thanks

Hi, if you look at the fault finding section of the manual for the CB24 and CB28 two flashing LED's at the same time will take you down the path of a faulty air pressure switch. In short, these do not regularly fail. What Alpha fail to explain is that the PCB is the likely cause and these are approx £180 to buy.

The good news is that you can repair them and it is nearly always the same component that fails - the Relay. The news gets better in that you can buy one for about £7.50 on ebay. Search for Takamisawa relay and you'll find them there. The job of replacement couldnt be simpler. Disconnect from the mains, disconnect the cables, remove PCB, heat the 4 pins on the back of the faulty relay (see pic - its the 3rd relay on the right) be careful not to overheat the conections when removing and use a solder soaker braid or solder sucker to extract the old solder, these cost aroud a £1.00 on ebay and then put the new one in (facing same way as the others) Reasemble in reverse order and you'll have a big smile on your face for days. Alpha CB24 CB28 PCB repair for less than a tenner. Winner.

Now Alpha wouldnt put that in their manual would they?

 

[Dotty]

Moved.

 

[Ermintrude]

isnt this a 105E in an alpha hat?