Cos HE24. Central heating will not turn off

[Stephanie]

Where do I start with this please? Fault developed around December and is intermittent. Everything is off. C is on and LED flashing. Tried everything on the control panel and turned on and off, turned thermostat down to virtually zero and it's still boiling away. Several hours later I have had to turn the boiler back on to heat the water and the radiators have come back on and are really hot, despite the panel being 'off' and thermostat down to its lowest setting. HELP!!
3 days later...fault is permanent and having to use on off switch to heat water, at which time CH is blowing the roof off Thank you for any advice in advance.

 

[ShaunCorbs]

Sounds like you might have a faulty port valve

 

[Stephanie]

Thanks, is this something we can repair ourselves?

 

[ShaunCorbs]

Thanks, is this something we can repair ourselves?

Depends how diy you are means draining down the heating, but testing the port valve first to check its at fault

Tbh it would be easier to employ the services of a plumber

 

[Stephanie]

Ok, I've had a look at photos of a port valve and it looks like the little box in the airing cupboard that has a lever on the top. It is currently set to 'auto' I guess it's worth moving that back and forth to see if it has any effect in the short term as it's not an emergency, but we'll get a plumber in anyway. Thanks very much for your help.

 

[Harvest Fields]

Depends how diy you are means draining down the heating, but testing the port valve first to check its at fault

Tbh it would be easier to employ the services of a plumber

Surely this might not be the whole valve. Maybe just a stuck motor? But then again I'm only young so I may be wrong? But as ShaunCorbs says would be worth getting a plumber

 

[Stephanie]

WD40 and a hammer?

 

[ShaunCorbs]

Surely this might not be the whole valve. Maybe just a stuck motor? But then again I'm only young so I may be wrong? But as ShaunCorbs says would be worth getting a plumber

Tbh don't know how old the valve is and it's just time head vs the body cost there not much in it tbh

I always change the lot as you know your good for about 5-6 years then

 

[Stigster]

Surely this might not be the whole valve. Maybe just a stuck motor? But then again I'm only young so I may be wrong? But as ShaunCorbs says would be worth getting a plumber

I'd just change the motorised head on a valve if the valve was in really good condition and moving freely. You should be able to move the spindle with just your finger tips basically. If it is sticking the new motorised head will fail as well.

If the valve body is not perfect, replace the whole assembly.

 

[Stephanie]

We've had it 5 years from new

 

[ShaunCorbs]

We've had it 5 years from new

I would change the head then aslong as the body moves freely

Do you know what make if valve is it (if no can you post a few pics up ) ?

 

[Stephanie]

Honeywell

 

[ShaunCorbs]

Does it have 3 pipes going into it or 2 ?

 

[Harvest Fields]

Tbh don't know how old the valve is and it's just time head vs the body cost there not much in it tbh

I always change the lot as you know your good for about 5-6 years then

True

 

[Stephanie]

Think I'm looking at the wrong thing as this as a block on the back with a pipe running in and out. Here's a few pix from tank cupboard

 

[ShaunCorbs]

Yes wrong one sorry, there should be another one

Looks like it's an old either danfoss or myson

 

[Stephanie]

Can see anything else in the tank cupboard

 

[Stephanie]

*can't

 

[ShaunCorbs]

*can't

Middle pic left bottom

 

[Stephanie]

The lever on top of the box on the bottom left moved freely in the 'auto' zone. It took quite a lot of effort to push it to 'manual'. I could hear a whirring sound, then another whirring sound when I pushed it back. Did that a few times and the lever now works freely without any whirring (probably broke it altogether!) Heating still the same, comes on when all dials are 'off'.

 

[ShaunCorbs]

Do you know how old that valve is ?

 

[Stephanie]

Approx 5 years, was new with the current system

 

[ShaunCorbs]

Approx 5 years, was new with the current system

Might just be able and lucky to get away with a port head replacement

Either way if your not confident get a heating engy in

 

[Harvest Fields]

I agree with the above. They are fairly straight forward. But if you are not sure then get a heating engineer in. If you give it a minute one of the sparky's will be along and let you know that a sparky can also change the head for you.

 

[Stephanie]

Thanks very much chaps, I learnt a lot today, including that I keep way too much in my airing cupboard

 

[Harvest Fields]

Not just you Stephanie. I think I have only ever been to about 4 houses where the airing cupboards have been completely empty with just the cylinder in them.

 

[Gazzt]

Get a plumber and they can test both zone valves and determine which one is keeping the boiler on. Dont try removing the actuator head as you can get an electric shock as there is a live feed to them. Get a qualified plumber to leave it safe and working properly.

 

[Chuck]

Others have covered the valve(s), but I will draw your attention to the system pressure gauge you show on the last picture, which at 0.2 bar seems much too low to me, I'd expect it to be around 1 bar when the system is cold. Ask your plumber, who will need to be on the Gas Safe Register, to investigate the root cause of this while they are on site.

In my opinion, you should not operate the boiler until this is sorted.

 

[Stephanie]

Others have covered the valve(s), but I will draw your attention to the system pressure gauge you show on the last picture, which at 0.2 bar seems much too low to me, I'd expect it to be around 1 bar when the system is cold. Ask your plumber, who will need to be on the Gas Safe Register, to investigate the root cause of this while they are on site.

In my opinion, you should not operate the boiler until this is sorted.

Thanks Chuck. I regularly open the valve and let water into the tank to raise the pressure but guess that ordinarily that shouldn't be necessary. My husband has called a plumber and I'll post the results when he's been. Thank you.

 

[moonlight]

The other valve which is on the heating looks like a danfoss valve, that is probably the more likely culprit.
The pressure gauge is for the heating system, and its on the low side. You have other issues that need addressing. I am pleased you have called a plumber

 

[Boilerbud]

Honeywell

Hi Stephanie

Disconnect white wire in junction box, heating and water off on timer if you have +- 160V on white wire contact Honeywell. Your 3 port head will be knackered but you also require another part which Honeywell will give part number for.

Sorry just saw you have s-plan so replace Danfoss heating valve complete.