Suicide pending re Central Heating Problem- Please help!!

[GIB984]

Hi all, been recommended to try you guys before I load the gun - LOL.

Basically I have been having problems with my central heating for ages now and its really doing my head in. I live in a 20 year old house and have a 3 year old Worcester Ri condensing boiler downstairs with a hot water cylinder on the landing, honeywell thermostat at the bottom of the stairs and a timer/controller in the kitchen.

It started with the rads getting hot when the timer was just set for hot water so I replaced the three way valve - easy I hear you shout.

That sorted that problem but then the boiler was also firing up for no reason at all when the timer was off and calling for nothing plus the radiators were burning hot and the room thermostat was having no impact at all. A little research later led me to the problem with the Worcesters firing up due to a low voltage return so my sparkie mate fitted the recommended farin supressor that cured that little problem. I then went on holiday........

Since my return the boiler has been coming on as requested for heating and hot water BUT the rads are still red hot and the room thermostat is having no impact at all - even when turned right down the boiler is still firing up and the rads get red hot.

I changed the Honeywell room thermostat for a new one but the problem still remains. My sparkie mate who wires boiler up has had a look at the thermostat and it is working correctly although it is having no impact on the boiler.

The only way I am coping (not very well) is to turn the setting on the boiler down in an attempt to reduce the temperature in the house.

The other problem is the boiler seems to be running permanently when on - it doesn't cut in and out and I have a humming/fan noise that is doing my head in. The noise isn't at the boiler or the hot water cylinder and I cant locate it despite trying hours to! It appears to be coming from somewhere between the floor as when I am upstairs it sounds like its below me and then when I get downstairs it sounds like its above me - AAAAAARGH!!!

Any ideas or shall I just load the gun and get on with it - LOL.

 

[doitall]

Not wired up correctly or a link hasn't been removed that should have.

Perhaps you need a proper sparkie that know about boiler electrics.

Some pics and info how what is wired to.

The boiler terminals is a good place to start. then the wiring center, room stat and programmer.

 

[Agile]

Seems to me a proper boiler engineer is needed!

 

[GIB984]

Hi, Thanks for that. My mate did do the electrical connections for boilers for a living but he openly admits he's not a heating engineer but the wiring has been checked and checked again and also the wiring has been as its been since installation with no previous problems?

He has suggested I get a new digital wiring centre though to eliminate that from the possibilities?

Would dodgy wiring account for the problems I am experiencing re the thermostat not controlling the boiler, the excessive temps and the noise?

Would a new PCB for the boiler be the next step?

 

[doitall]

Something tells or is telling the boiler to come on, and I would certainly suspect a wiring fault.

 

[GIB984]

Something tells or is telling the boiler to come on, and I would certainly suspect a wiring fault.

Do you mean within the time period when it is actually timed to be on , as it is going off when its supposed to?

 

[garethpa]

first port of call would be to disconnect the thermostat from the boiler (including its wiring), then see if the fault is still there.

 

[Phill Peck]

Probably zone valve giving permenant live to boiler

 

[GIB984]

Probably zone valve giving permenant live to boiler

Hi, just to clarify - are you meaning a permanent live during the period when the boiler is timed to come on?

Only because the boiler isn't coming on outside of the times set on the timer?

 

[D_Hailsham]

He has suggested I get a new digital wiring centre though to eliminate that from the possibilities?

If your mate called it a "digital wiring centre", I would be very suspicious of his abilities; there is no such thing! Just as there are no such things as "digital aerials" or "high definition aerials"!!

A wiring centre is a wiring centre.

 

[matt1e]

It started with the rads getting hot when the timer was just set for hot water so I replaced the three way valve - easy I hear you shout.

That sorted that problem but then the boiler was also firing up for no reason at all when the timer was off and calling for nothing plus the radiators were burning hot and the room thermostat was having no impact at all

Are you sure it sorted it?

Since my return the boiler has been coming on as requested for heating and hot water BUT the rads are still red hot and the room thermostat is having no impact at all - even when turned right down the boiler is still firing up and the rads get red hot.

Because it doesn't look like it mate

I changed the Honeywell room thermostat for a new one but the problem still remains. My sparkie mate who wires boiler up has had a look at the thermostat and it is working correctly although it is having no impact on the boiler.

Thats because it's supposed to impact on the 3port valve first although it does indeed impact on the boiler when the valve is in the CH position

If your rads are getting hot when just hot water is called for then it's a problem with the valve or valve control wiring
who replaced and wired the new valve ?

The other problem is the boiler seems to be running permanently when on - it doesn't cut in and out and I have a humming/fan noise that is doing my head in. The noise isn't at the boiler or the hot water cylinder and I cant locate it despite trying hours to! It appears to be coming from somewhere between the floor as when I am upstairs it sounds like its below me and then when I get downstairs it sounds like its above me - AAAAAARGH!!!

are you sure it's not the pump you are hearing?
what model is the boiler?
Is your hotwater ok or is it getting too hot

anyway my money is on incorrect wiring
turn off the ch system at the spur/isolator, check that the valve has returned to the hotwater position if it doesnt then its jammed open (or theres still power to it)
now disconnect the valves white wire and make safe then turn the power back on and select hotwater if the rads now get hot the valve is faulty or fitted the wrong way around
if the rads stay cold then you have a wiring fault

Matt

 

[GIB984]

Thanks for all the help and apologies for any confusion or misleading from inaccuracies in my posts due to my unfamiliarity with the topic and lingo.

So:

The term 'digital wiring centre' was mine not my mates.

The three way valve functions fine I think - it correctly switches between CH and HW. I don't get the hot rads when only HW is timed to come on and the temp of the hot water out the taps is as normal.

The boiler is a Worcester Greenstar RI - I'll dig out the paperwork to find the exact model.

Thanks again for all the suggestions and advice

 

[matt1e]

Thanks for all the help and apologies for any confusion or misleading from inaccuracies in my posts due to my unfamiliarity with the topic and lingo.

So:

The term 'digital wiring centre' was mine not my mates.

The three way valve functions fine I think - it correctly switches between CH and HW. I don't get the hot rads when only HW is timed to come on and the temp of the hot water out the taps is as normal.

Ah its a bit clearer now thanks
the temperature of the water in your rads is set by the boiler thermostat as you have found
so we are left with the problem with the room stat/wiring, do you have a multi meter? as I think the wiring at the valve would be a good start checking
if not, then for a quick check,
power off at the heating spur/isolator to reset the valve and select HW off and CH off at the programmer then power on the system spur
now go and have a look at the valve it should be in the hot water position but I suspect it will be in mid position as it sounds as though the valves white and grey wires are mixed up

Matt