Hot Water/Combi Boiler Problem! (Merged)

economiser

dilloman wrote: »

Hi
I have an Alpha combi boiler. The system is losing pressure to the point where I need to manually re-pressure it every day and sometimes twice or three times a day. The heating stays on once it is re-pressurised but once it is off the pressure seems to drop rapidly. I've tried bleeding the radiators but no air was found (radiators were hot anyway). I'd be grateful for any advice.
P.S. Great site!

I would suggest you check the air pressure in the expansion vessel. Isolate and drain down boiler and check air pressure. Don't know what they recommend with Alpha but Vaillant is 0.75 bar. If low, or as I suspect next to nothing, pump up to recommended value. Should be possible with a car foot pump. Then refill boiler and bring pressure up to recommended system pressure with water valve, probably about 1.2 bar. If problem recurs try replacing valve in pressure vessel before you get into changing pressure vessel, they rarely fail.

fizzy69

Have an Alpha boiler CB24/28 located in my loft and have had trouble with it for the last couple of years, it has now got really bad and sure could do with some advice please.

The system is losing pressure up to three times a day, it seems to be letting all the water out of the overflow pipe in the wall, i fill the pressure up to get the system working, use the central heating turn it off and within two hours it is not working and the pressure is too low.

Have had fitted in the past diverter valve and diagphram, which was in the summer and it had been ok until this cold weather, do not know if maybe part has gone faulty again or problem is somewhere else.

I DO know it is a pain having to climb up the loft daily to refill system with water.

Please reply if you can help.

Canucklehead

Hi

See post above yours.
You will also need to replace or clean the pressure relief valve and put more inhibitor in the system. If you have been doing this for sometime then the system will have got quite dirty now.Flush it, and or fit a Magnaclean.
Corgi Guy.

furryfeet1690

I have an Intesa TP 23 Combination Boiler. Any time i run hot water from the tap or put on my central heating the ignition sequence fails to start on the boiler. The pressure and power is fine, it just switches itself off after failing the ignition sequence. Please help!

Canucklehead

furryfeet1690 wrote: »

I have an Intesa TP 23 Combination Boiler. Any time i run hot water from the tap or put on my central heating the ignition sequence fails to start on the boiler. The pressure and power is fine, it just switches itself off after failing the ignition sequence. Please help!

Hi

I would start with the ignition probes and the leads to and from them.
A good service would find any problems like this.
Next would be the overheat possibilities.

Corgi Guy.

Caz1982

Hi

I'm having problems with my combi boiler. Sometimes it works fine, we have central heating and hot water, then other times it cuts out, we have no hot water or heating. Sometimes we have hot water but no heating.
It has come to the point where we were having to push 'trip button' to kick start the boiler but now that sometimes has no effect.

A plamber came to look at it but at the time it was behaving and he said maybe it was a 'sticky valve' but he wouyld have to come out and see it when its not working. But that is tricky as sometimes it comes on in half an hour, sometimes it hours or days!

Anyone able to help?

caroline,

EricOlvr

my ferroli optimax combi boiler is acting up the water doesn’t reach the right temperature it gets so far then cuts out then warms up again then cuts out so the water goes hot and cold the hole heating system seams to be the same I’ve just replaced 2 valves on the radiators that seemed to be leaking but the heating isn’t reaching the right temp

Forever_Red

economiser wrote: »

I would suggest you check the air pressure in the expansion vessel. Isolate and drain down boiler and check air pressure. Don't know what they recommend with Alpha but Vaillant is 0.75 bar. If low, or as I suspect next to nothing, pump up to recommended value. Should be possible with a car foot pump. Then refill boiler and bring pressure up to recommended system pressure with water valve, probably about 1.2 bar. If problem recurs try replacing valve in pressure vessel before you get into changing pressure vessel, they rarely fail.

I have a Vaillant combi boiler which is losing pressure on a daily basis. Checked all valves and radiators but no leaks anywhere. When I pressurise the boiler to 1.5 bar and turn on the heating, the pressure starts to go up to 3 bar.
Does this happen if the air pressure is low in the expansion vessel? Can a general DIYer pressurise the expansion vessel or is it best to get a plumber in?

Any comments appreciated.

Alan

eirotsnawe

economiser wrote: »

It sounds like the diverter valve. This is quite a common problem with combis. When you turn on the hot tap the boiler has to divert the incoming cold water through the heat exchanger in place of the heating system water and the valve that does this sometimes gets stuck.

I have the same problem in that the hot water doesn;t heat up.. However the hot water for the shower etc works if i use the "1hr boost" button on my combi boiler... Would this be the same diagnosis??

skinflintmida

hi there, i have a ferroli domicompact f24b and its about 3 years old and has started to go hot and cold when having a shower. it can do this about 3 to 4 times in a 5 min shower. ran a bath to elimanate mixer block, hot and cold again! kitchen sink does the same! expansion vessel has 1 bar in it. radiators are always nice and hot but the japanese water torture shower is too much! please help dont mind having ago myself but dont just want to through money at it!
:snow_laug