How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Andrew Smith Your Own Question
Andrew Smith
Andrew Smith, Plumber
Category: Plumbing
Satisfied Customers: 3767
Experience:  City and Guilds qualified plumber
Type Your Plumbing Question Here...
Andrew Smith is online now

My hot water is working fine, but the heating (set on timer)

This answer was rated:

My hot water is working fine, but the heating (set on timer) isn't activating at all. So far I have checked:-
Boiler isn't on summer programme.
New batteries on thermostat in hall way.
No error readings on boiler.
I don't know how to put the boiler onto constant to check that?

XXXXX XXXXX : Do you have an RF receiver box under the boiler?
Customer: I don't think so? Just piping.
XXXXX XXXXX : Do you have the make and model of the boiler?
Customer: Biasi activ A30c
XXXXX XXXXX : Can you take the transmitter off the wall and sit it under the boiler, take out the batteries
XXXXX XXXXX : Turn off the power to the boiler at the fused spur
XXXXX XXXXX : Leave off for 5 minutes
XXXXX XXXXX : Turn the power back on
XXXXX XXXXX : Replace the batteries and leave the unit under the boiler
XXXXX XXXXX : Let me know what happens?
Customer: I have unscrewed the unit, from the hall, and brought to the kitchen, but the wiring to the unit is still on the wall in the hall. Would need a sparky to take that off? Will follow above instructions now
XXXXX XXXXX : Ok, leave it as it is then.
XXXXX XXXXX : Can you confirm if the boiler has a pressure gauge?
XXXXX XXXXX : I thought it was an RF thermostat (radio frequency - unwired)
Customer: Yes it does, it displays underneath the boiler. I think it is where it should be, around 1.5
XXXXX XXXXX : Do you get a click from the thermostat when you turn the temperature?
Customer: Yes.
XXXXX XXXXX : Ok, a problem with the stat or the wiring needs to be ruled out now before we start on the boiler
XXXXX XXXXX : Can you take the stat off and tell me what wires are at the backplate and which connections
Customer: The stat came off the wall easily, with no wires connected to it, but the back plate has wires, blue, yellow red and a copper wire. I think the plate has three flat 'prongs' which go into slots above the wires, so similar to a plug?
XXXXX XXXXX : so left to right blue, yellow, red and earth?
Customer: No, red on the left, then a space, then an empty one, then yellow then blue. The copper is just folded at the bottom?
XXXXX XXXXX : If you turn the power off and take out the red and place it in the same connection as the yellow, turn the power back on and tell me if the heating fires?
XXXXX XXXXX : That links out the thermostat
Customer: Turn the power off at the mains fuse box?
XXXXX XXXXX : The boiler spur
Customer: Ok, if not back in 5 call an ambulance #sparky extraordinaire!!
XXXXX XXXXX : I will wait for the explosion - will I hear it in Nottingham?
Customer: So, the red wire isn't long enough to go to the yellow wire, can I put them both in the red wire slot?, if not how can I get more red wire? I've tried pulling (gently) but it goes into the wall, and there is no give
XXXXX XXXXX : As long as they both are connected together it will rule out the stat
Customer: So, the boiler sort of fired, as it does when switched back on, but the heating isn't on. I didn't put the front plate back on tho? Should that matter?
Customer: Front plate of the stat
XXXXX XXXXX : No it shouldnt
XXXXX XXXXX : If the boiler hasnt been doing that with the stat on then the stat is faulty
Customer: Can we buy a new one?
XXXXX XXXXX : Perhaps there is a problem with the boiler too - any fault codes when the boiler is firing?
XXXXX XXXXX : As you say you have no heating?
Customer: No fault codes showing
Customer: I think my boiler thinks it's summer time, but is displaying water and heating icons.
XXXXX XXXXX : Perhaps it just made noises because you turned the power back on, does it make the same noise if the stat is connected the same and you interrupt the power?
XXXXX XXXXX : I take it the heating is still working?
XXXXX XXXXX : *hot water!
Customer: Yes the hot water is fine still.
XXXXX XXXXX : Right, lets put everything back together the way it was
XXXXX XXXXX : I need you to take the case off the boiler and tell me if the pump is running when the heating is supposed to be on?
XXXXX XXXXX : If the pump is not running then it sounds like the divertor valve is faulty, when the stat tells the boiler to fire,
XXXXX XXXXX : the divertor valve should then tell the boiler it is in ch position and fire
Customer: Ok, but how does the boiler know it is supposed to be on, if the timer is saying it shouldn't. Do you mean when the hot water is running, or just if I increase the temp on the stat, and hear the 'click'.
XXXXX XXXXX : From inside the boiler when you run the tap?
XXXXX XXXXX : Or when the pump runs - there will be a flow switch to fire the boiler when the pump runs
XXXXX XXXXX : Does the pump run when you open the tap?
Customer: Called a gas engineer earlier today. Couldn't fix it. Thinks it's the circuit board. Didn't work when he bypassed the stat, by connecting the boiler directly. Going to get a new boiler as the make isn't a good one and the parts are too expensive and wait time too long.
Andrew Smith and other Plumbing Specialists are ready to help you