Alpha 25C Heating Not Working

[Frelon]

Hi

My daughter and her husband have just bought a house in Brighton in which the previous owner had installed an Alpha 25C boiler.

The heating failed last week (hot water still available) and the engineer diagnosed a faulty diverter valve head because there was a slight leak from the diverter valve. Valve actuator replaced.

Two days later still no heating! The poorly designed wireless thermostat (Alpha 24 hr Easystat) is demanding heat, the red light is showing on the boiler, but no hot water for the heating system is being produced.

We are awaiting the return of the engineer who diagnosed the problem last week, but in the meantime are looking for a heating engineer who does not make a sharp sucking in of air noise when he realises that an Alpha has been installed!

.....and if anybody has any ideas regarding a replacement thermostat where you can actually see what temperature settings, and whether the thermostat is demanding heat, without looking at the boiler, we would welcome them.

 

[Alpha man]

lol, Drayton wireless RF601.

 

[AWheating]

an alpha................tut, tut.........tut. 🙂

 

[Whn1]

Aouchfa.....

 

[Frelon]

Hi Alphaman

Is the Drayton RF601 directly compatible with the Alpha CD35C?

I am presuming that the receiver on the Alpha will need to be replaced by the Drayton SCR?

Many thanks.

 

[lame plumber]

just check for large metal objects next to the transmitter whixh can corupt the wireless link and try changing the rf freq on the tx/rx often your neighbours wirless computer links can interupt a wireless signal as well

 

[TBServices]

just check for large metal objects next to the transmitter whixh can corupt the wireless link and try changing the rf freq on the tx/rx often your neighbours wirless computer links can interupt a wireless signal as well

Such as a boiler?!? Lololol

This is why I use Honeywell every time, never had interference!

 

[Alpha man]

The Drayton is a non Alpha part, and is external to the boiler, simple external wiring and away you go!

 

[Frelon]

Thanks Alphaman, that's what I thought.

Have need experimenting today with my Alpha controls in an attempt to get some heat!

With the selector switch set to 2, there is no heating....

I have, as the engineer suggested, turned the switch off, waited a bit and then turned back on to 2. Result was a bit of gurgling in the boiler and then nothing!

However, if I turn the system off (switch position 0) and wait for 10 to 15 minutes, then turn back on to position 2, it seems to initiate the diverter valve and hot water is starting to circulate through the heating flow. Yippee....

That's good until I make a hot water demand at the kitchen sink.......and afterwards no heating....

OK chaps, those are the clues, over to you.

BTW for the purpose of the test the thermostat (portable) is in the same room as the boiler and the red light on the receiver is lit.

Thanks in advance for your help.

 

[Plumb Ugly]

If the red light is on the receiver its getting the signal from the stat. Could be a fault with the receiver not giving demand to the boiler needs testing to confirm if there is a fault on the boiler or heating controls

 

[Alpha man]

Room stat has locked out, have you renewed the batteries in the easystat? and then reconfigure the transmitter to the receiver? If you have and its still not working, the eaststat is fooked!!, isoate the electricity at boiler, and disconnect the 2 red wires on the easystat transmitter and link both together and then you will have heating, but will have to turn on/off via the selector knob! But if unsure what you are doing with the wiring, leave it alone and get a GSR engineer in!

 

[Frelon]

Yes, the engineer replaced the batteries on the remote.

When you say "disconnect the 2 red wires on the easystat transmitter and link both together", did you really mean 2 red wires on the RECEIVER?

The Drayton RF601 is looking very attractive at this stage!

 

[Frelon]

Thanks Alphaman, it seems the Easystat is unwell. Very unwell, but I like your description better!

Took all precautions (switched off system at mains before opening front) disconnected the red wires on the back of the receiver, joined them together (carefully insulating them) and fired up the system. All worked as required, hot water on demand and heating when selected manually.

Tried to reconfigure the transmitter to the receiver but it was not having any.......so all in all time to bin the Alpha wireless thermostat and receiver.

......engineer coming tomorrow with replacement lead for diverter valve actuator and new PCB!!!!!

Another gold star for Alphaman. My daughter is eternally grateful. Thanks.

 

[Alpha man]

My pleasure Frelon!

 

[Frelon]

An update for Alpha Man, and any other interested readers!

Sadly the success was short lived.......yes, the heating was working but as soon as there was a hot water demand hot water was diverted to taps and never got diverted back when hot tap was switched off!

I still have the remote receiver bypassed and am relying on manually selecting hot water/heating. Hot water always works but selecting heating may take several goes to get the heating flow activated. Once heating is activated we hold our breath just in case we need to draw off some hot water which may kill the heating.

Heard from the engineer this afternoon who still thinks it may be the lead for the diverter valve actuator......or the PCB. Neither in stock at present so may be a few days before he can get back......

So, is it possible for the diverter valve to stick in one position or the other? Seems like it gets stuck in the hot water mode and is temperamental as to whether it will divert to heat mode when asked. Or am I being too simplistic?

There are the clues chaps (and chapesses) your input is appreciated.

 

[Plumb Ugly]

The diverter rests in the hot water position when there is no demand for heating or there is hot water demand

 

[Frelon]

Thanks PU, that explains that, so there is a priority for hot water.

I am getting a real education here!

 

[Alpha man]

If your engineer removes the divertor motor from divertor valve, does the heating then work?

 

[Plumb Ugly]

Yes the actuator simply moves the valve into the heating postion when there is a demand for heat. This movement is blocked if there is also a demand for hot water giving priority

 

[Frelon]

Alpha Man

The engineer replaced the diverter motor a week ago because the old one was a little damp. However this did not solve the problem hence the call back.

During the second visit he removed the diverter motor and observed the actuator while I was cycling the hot water on and off. He observed that the actuator was not doing what it should do when I turned the hot water demand off. First thought was that the new diverter motor was faulty so a replacement was tried with same results.

We did not try the heating whilst the diverter motor was removed.

It was then decided that the diverter motor was not receiving the correct command, first thought being a break in the motor lead, and failing that a replacement (at high cost) PCB. Still no understanding of what is causing the diverter motor not to work

 

[Plumb Ugly]

Best bet is to test the votage from the pcb when it is supposed to be moving to the heating. Get you engineer to test this next time to determine what's a fault

 

[Dannypipe]

Just been to look at a faulty Alpha CD25C.

Do Aplha do fixed costs repair? This boiler was in a bit of a state when I opened it up, it's only a few years old according to the client. Its gonna need a couple of parts minimum. Its leaking from the diverter, everytime the spindle is depressed. So the whole bottom of the boiler was in a pool of water.

I've advised customer to contact Alpha.

 

[Plumb Ugly]

I believe they do probably a few hundred though but can be the best course for the cust if a few expensive parts are needed

 

[Dannypipe]

Thanks.

Yes, this one is going to need a good few parts. Flooded from the inside out. Would suggest a new boiler if this one wasn't only just out of warranty!!

Cheers

 

[Plumb Ugly]

Crazy isn't it you could probably buy a new one for the price of a few spares! Cheap boiler and expensive parts:32: