Thermostat programmer off, CH still switching on and off

[Aheardie]

Hello

Hope someone will be able to help please....
About a month ago, we had a problem suddenly where the CH programmer was working normally, but only the radiators upstairs were heating, no heat at all coming from the downstairs radiators. Called a vaillant engineer out (we have a vaillant Ecomax boiler) who came and replaced the pump, and actuator head, and left having not solved the problem. However, later on in the day, the heating switched on by itself...including the downstairs radiators. Since then, even with the programmer (cm67 honeywell) switched completely off, the heating just comes on and off whenever it wants.
Any ideas, how or why this is happening, and what could be causing this please? Do you think it could be the thermostat or still the boiler, that is the problem?
(In november the engineer came out, and replaced the expansion vessel, auto air vent, p c b and the pump.)
Many thanks in advance for any help!

 

[Abcplumb]

Hi

You have a programmable wireless room state, if I'm right.
Sometimes these devices can lose pairing.
You need to check this, once this is confirmed look at the boiler when you are NOT calling for heat. What does the display say?
Also confirm the model number of the boiler.
Try to provide as much information as possible.

regards
Al

 

[Aheardie]

Hi Al

Thanks for your reply...really appreciate your help.

For the devices to lose pairing....does that mean connecting each other....ie boiler and thermostat programmer? Sorry for the daft question! If that is the case.....how would I check this please?
The boiler is a valiant, Ecomax 828E. I've just checked it now, and the programmer isn't calling for heat, the boiler reads 0 53.
The boiler is situated in our loft, and the programmer is downstairs in the dining room.
I have left the programmer switched to 'off' for quite a few days, but the radiators still warm up a couple of times a day. Usually about 630am, then again around lunchtime, again about 7pm, and then about 10pm. The room heats to about 23c!
(I have replaced the batteries in the programmer).
Thanks

 

[Abcplumb]

Hi

Wireless devices can lose pairing, specially room states. I am not familiar with the one you have, but there could be a display which should state if it has lost pairing with the unit at the boiler. Its best to read the manual for your device. If you don't have it, you should be able to download if of the Honeywell site.

When you say, the boiler reads 0 53.
Do you mean S.03, as this is a status code, which is displayed when you press the "i" key.
The "i" key is located on the top right of buttons on the display.
Please check this again.

Also check it the radiators are warming up when you are using the hot water as this can indicate another fault.
Maybe when someone is using the shower?
Are all the radiators heating up when this happens?
Is the water heating correctly? ie, temp?

 

[Aheardie]

Evening!

Checked the boiler again, and also checked the manual for the codes, "0" means that the external controls aren't calling for heat, and the 53 is the boiler flow temperature.
The radiators don't seemed to be coming on when the hot water is being used.....thought first thing this morning this could be the case, but double checked a few times throughout the day, using shower, and washing machine etc, but they weren't turning on.
All the radiators are turning on whenever.
The hot water seems to be getting to the right temperature...warm enough for showers etc. Although doesn't lat very long.
Can't find in the manual anything to do with connecting to the boiler, it is mainly just basic programming stuff. I have tried "googling" it, and even the instructions from honeywell as just the basic stuff.
Thanks again
A

 

[Abcplumb]

Hi

If you are certain that the heating is not coming on when you are using the shower, then we can look at other possibilities.
You have to be 100% sure otherwise we'll be going round in circles.
If your heating is not coming on when someone is using the showers then you know your diverter valve is fine.
The other issue I can think of is a fault on your honeywell device.
I would suggest to disconnect, and revert back to the way the boiler was before the wireless thermostat was installed. You may need an electrician or a boiler engineer. It shouldn't take more then 10mins.
Once removed if the fault persist then i would suggest a fault on the P.C.B.
In the mean while you can turn the heating temperature dial all the way anti-clockwise.
Maybe you want to try that 1st, this way the heating should not come one even if your device is calling for heat.

 

[Aheardie]

Hello
My husband has just had a shower...and the only radiator that I haven't been able to turn right down today....because of the weather, is the one in the bathroom (towel radiator) and that one is hot. The programmer is still switched completely "off". Sorry for being unsure.....it just seems to be so hit and miss.
I'll keep a further eye on it tomorrow, and not run the washing machine, and just try and suss it if it is just with the showers. If the heating is coming on when the showers are running, what does that actually mean....?
We have only been in this house since aug last year.
There isn't a dial on the boiler, as it is digital, but I can turn it down to summer temperature, although first need to check this won't effect the hot water.
The p.c.b was replaced in November last year.
Thanks again...really appreciating all your help.

 

[Aheardie]

Sorry just re read your message, that it could be the diverter valve, if it is connected with the showers being used. Is that the case with just showers or any big water usage, ie dishwasher and washing machine?
Thanks
A

 

[Abcplumb]

Hi

Any large amount of hot water usage will confirm the diverter valve fault.
Washing machine is not a good one, as some machines heating the incoming cold water, so there is no hot water used by the washing machine, same for the dish washer.
The best way to confirm would be early morning when the boiler has not been in use. Check all the rads make sure they are cold, that's if you havnt turned off the TRV valves. Or you can just check the bathroom radiator. Use the shower, I assume this is not a electric shower? Right? Please confirm.
If the water in your shower is provided by the boiler then we can continue.
Use the shower for at least 10mins then touch the bathroom radiator, if this is heating up then I think its your diverter valve.

 

[Aheardie]

Hi

The shower is not an electric one, the water is heated from the boiler. I will check the bathroom one, as I have turned down all the TRV valves, first thing in the morning, before and after the first shower.
(Our washing machine is connected to a hot and cold water tap, so isn't heating the incoming cold water).
If it is the diverter valve, would it be better for me to call out the vaillant engineer, or a plumber. Would you know how much this could cost to fix, please?
Thanks

 

[Aheardie]

Also, would the diverter valve override the cm67 programmer??

 

[Abcplumb]

The diverter valve function is to "divert" the heated water to the hot water or the heating, if this is faulty then the heated water would be passing into the central heating when it should be fully passing in the hot water.
Its a very common fault on these boilers, it does suggest the system need powerflushing.
The valve should cost around £40-£70
and labour approx £80.
shouldn't take more than an hour.

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