Alpha CB24 Problems.

[mattbwell]

I dont know whether anyone can help, We have a few problems with our boiler, sometimes the hot water will just go cold half way through a shower, and takes agers to come hot again. and it leaks water from the over flow consantly which is hot when the heatings on.

We had a plumber who changed the miccro switch and sensor. and I but the old micro switch back on and there hasnt been any change so the switch must of been fine in the first place.

 

[methaneman75]

sounds like the expansion vessel regarding the water being discharged from the blow off pipe, i take it the pressure on the front panel is at 3 when this is happening.
there is plenty of info on this site regarding recharging an expansion vessel but if you are toiling i will write out a procedure for you.
more info needed on hot water, is it ok at other hot taps

 

[methaneman75]

i have just noticed you have wrote constantly but is that constantly when heating is on or just constantly and is only hot when the heating is on

 

[mattbwell]

It runs constantly and only hot when the heating is on, I realised the presure and it tops up to 3 bar and slowing trickles out, I had to put a hose on it so it goes down the drain.

As for the hot water It is the same for all the taps. You can run it and it will be fine but some days it starts running hot then after 3 mins it goes cold, then you have to turn the tap off and wait for a bit then try it again to see if it gets hot.

Its been a nightmare we have only had it for about 5 years.

My dad was a gas fitter so he kept the last boilers going for 30 years. but unfortunatly he past away 7 years ago. So we ender up having the combi put in.
It was leaking water when the plumber came last year and he said it was ok, but surely its not. Bloody modern technolagy. lol

 

[mattbwell]

on the combi its the gauge reads 1.25bar,
and we have a pressure gauge where the mains water for the heating before the combi was but in and that reads 2.5 bar.
and theres no expansion vessal. Our house comfuses everyone.

 

[apb]

i would check for the following faults


if as you say when you released the pressure it tops up then i would say that the fill and loop is turned on or passing

if this is the case you may have damaged the diaphram in the expansion vessel causing the vessel to lose pressure

a combi boiler realise on constant pressure not continuess pressure they have to be filled to 1.0 to 1.5 bar depending on the model which in turn will expand by the volume of air in the expansion vessel normally 1 bar to maintain heat if there is a continues pressure i.e the boiler is constantly filling then the thermistors and sensor will not be able to identify correct temperatures

as for the hot water i would change the hot water sensor about £15 from any reputable heating suppliers turn of the cold water supply and drain then change if you are un sure of this job call a reputable engineer i would say that it would cost no more than £85 supplied and fitted

 

[gas4you]

See FAQ's on how to check/test an expansion vessel. We mean the one in the combi, they all have these.

 

[mattbwell]

Thanks for all the advice! I found out today that it stops leaking when the hot water is running. So its defantly a problem with the hot water.