Page 1 of 1
No HW or CH
Posted: Sat Mar 22, 2008 11:07 am
by droney
I have a old central heating system that has a back boiler ,seperate hot water cylinder and a vented water tank in the loft.
Both my hot water and central heating have packed in.I have a drayton timer switch that powers up ok as it should.If i select either hot water or central heating on it ,the switch lights up as usual and appears to work fine,but nothing else happens.
Anybody any ideas what would cause both the HW and CH to fail? I have located the pump under the floor and gave it a couple of taps as was suggested by a friend of mine but it made no difference.
I suspect it could be either the pump,back boiler or immersion heater in the cylinder at fault.
Any help appreciated to point me in the general direction.
Posted: Sat Mar 22, 2008 4:53 pm
by htg engineer
is the pilot light still on ?
Posted: Sat Mar 22, 2008 7:09 pm
by droney
The house is old and the back boiler is situated in the chimney breast behind a gas fire.The gas fire works ok.
Im not sure how to check if the pilot light is on as you cant see the boiler and im not sure how you would light it.
All my previous systems have been combi boilers in previous houses and they were straight forward.
Posted: Sun Mar 23, 2008 8:59 am
by htg engineer
That's what you need to check - if the pilot is off, then that'll be why you're getting no heating or hot water.
That's the first (simple) check - if the pilot is still on then it could be a list of things.
If you're that unsure - get an engineer out.
You said you tapped the pump ? is the pump running ? even if it wasn't - the boiler would still fire up for a few minutes.
Posted: Sun Mar 23, 2008 3:16 pm
by droney
Im pretty sure its the pilot light that is out.Ive tried to light it as per the instructions without success.When i press the grey knob i can hear the gas flow and i can see the spark when i press the igniter button.It doesnt seem to want to light although it is very difficult to see.
Ive held the grey button(gas ) for at least 15 seconds and a lot more.Is this as far as i can go myself or is there anything else i can do?
Posted: Mon Mar 24, 2008 6:28 pm
by htg engineer
What's the boiler make and model, lighting with a match or taper is not advisable, but you can get igniters for hobs etc which only provide a spark. They are about 8" to 10" long, so should reach.
The spark electrode may have moved, the pilot may be partially blocked or the spark generator may not be providing a strong enough spark to ignite the gas. This could be why the pilot will not light.
Lighting the pilot may not be the end of your problems, unless it has just blown out.
It could be the thermocouple or gas valve at fault.
Posted: Mon Mar 24, 2008 8:22 pm
by droney
Hi, the boiler is a Baxi Bermuda SL3 (401boiler).
There isnt a lot of room to get your hands in ,although an igniter may reach.I assume that its not enclosed where the pilot light is situated?
Posted: Thu Mar 27, 2008 9:09 pm
by droney
I have removed the fire facia and can now see the pilot light okay.I can get this to light everytime i try now but as soon as I release the grey gas knob the light goes out. It alwaysd lights straight away but will not stay on.
I followed the instructions and turned the grey gas knob to the right instead of pushing it in and waited 3 minutes but the same problem keeps happening.
Posted: Thu Mar 27, 2008 11:50 pm
by matt h
THE FAULT IS THE THERMOCOUPLE. i ADVISE THAT YOU GET THE SYSTEM SERVICED. CHECK YOUR HEADER TANK IN THE LOFT TO ENSURE NO BUILD UP OF DEBRIS. ENSURE HEADER TANK HAS BYELAW 30 KIT FITTED. ADVISE GENERAL MAINTENACE EVERY THREE YEARS; DRAIN DOWN ENTIRE SYSTEM AND FLUSH OUT, AND THE TOP UP AND ADD INHIBITOR