Alpha 240E hot water

[spamse]

Hi all,

I have an Alpha 240 Eco that has stopped supplying hot water, but fix doesn't seem to be the obvious. CH works fine, when you switch the hot tap on, it dies. The diverter valve was replaced about a year ago, and is working fine. The microswitch on the front of the valve seems fine - I cleaned it with switch cleaner to be sure, but if pressed manually the boiler fires up. However, despite the switch being activated by the diverter valve, it won't fire up with water flowing.

I am reluctant to pay for yet another call out as the diverter cost me £200 (seemed OTT to me), and I have since had to spend more on replacing the fan and injectors. If there is someone in the area who can work for sensible rates, please contact me! Otherwise any pointers would be useful if it is a potential DIY fix. I am happy with a soldering iron and multimeter so would do any PCB work.

Cheers
Sam

 

[Gasguru]

Are you sure the switch is OK.

Does the pin move out sufficient to operate the switch?.

Remove the switch fron the front section of the diverter and open a hot tap. It should be difficult to press the pin back if the diaphragm is ok.

£200 to replace the complete diverter with a new one is a very reasonable price given the price of a genuine new valve.

Not sure why you'd need to replace the injectors - only ever needed on very old boilers ie 20/30 years old.

 

[spamse]

The boiler is probably about 12 years old (that's a guess based upon how long the previous owners were here).

The switch on the diverter is fine. Some more info though - I have noticed that the pin on the valve behind the diverter (the pressure valve?) pushes fully out when running CH, but doesn't fully extend for hot water, hence is not activating the switch. Could be the washer or diaphragm in this one? It is not water pressure as I have tried cranking this up but without success.

I presume I am not allowed to do this repair myself? (I'm not a plumber, as you might have guessed).

Thanks,
Sam

 

[ChrisR]

Most ppeople assume they can do everything!
You can do whatever you like, as long as you're competent - and you're the only judge of that who matters unless it explodes, whch is a tad unlikely for this!

Either, um, the pump is getting tired, there's a flow restriction such as sludge in one of the heat exchangers, or the pin on the switch itself is sticky.

 

[spamse]

Thanks for the info. The pin on the pressure valve presents a fair amount of resistance if I try and push it in whilst on CH, but on HW it is easy to push back in. I tried applying some lubricant from the outside to help it move freely, but it is simply not pushing out far enough to activate the switch. For the minute a thin slither of paper is offering the extra leverage to make it work...
It sounds like the diaphragm is the problem - does this sound like the right conclusion? If it is sludge that is the problem, I am not sure how to go about solving this, and I am hoping the pump isn't the problem. If it is fairly straightforward to replace the diaphragm I will go ahead and buy a kit to replace it and do it myself, but if there are complications I could get an engineer in.

Thanks,
Sam

 

[spamse]

whoops, duplicate post

 

[ChrisR]

Well if you look at the book you'll see that if the DV is letting by to CH the pressure could be low at the sense point , so shut the CH flow isolator to try it. It might weep, but only for a day or so, honest.

I'd check the rpm of the pump and try another capacitor across the one it has (first), but assuming you can't do that, get a new pump (head).

 

[spamse]

Thanks for info. I don't have a manual yet, Alpha have not responded to my request for one.

I am not sure which the CH flow isolator is to try this test. If the pump needs replacing, what sort of cost should I expect? I seem to remember being warned by the last repair guy we had in that it would be prohitibively expensive, but I can't see why - its just a generic pump.

I think I will have to get a pro in to have a look, under pressure to get this solved by my wife. Useful to get advice here though as I have found it hard to get enough info out of the repair men to understand the issues, and obviously I want to make an informed decision about whether to keep spending on this old boiler. We are in the process of trying to move, and have recently handed over a certificate to the solicitor from the last service to say that it is all ship-shape - obviously very inconvenient that it has broken down now, and you will understand my reluctance to shell out more cash on it.

Cheers,
Sam

 

[ChrisR]

CLick on the link & pic I gave you. The flow pipe is as shown, the leftmost one.

The boiler water should go round the blue circuit, in HW operation

 

[Agile]

You could remove and clean the plate HE as thats the most likely cause.

Alternatively ( or next ) remove the pump head and see if there is any dirt stuck in the impeller.

If the pump is clean then run it out and do the finger test on the torque. Should be in the FAQ here.

Tony

 

[ChrisR]

do the finger test on the torque. Should be in the FAQ here

Is it?