Go Ahead With Evohome purchase/dealer install or get problem fixed first

[donzo44]

Hello all

Just joined so apologies if this is in the wrong place.

Wife and I are getting on a bit so need the heating! Sorry if this sounds long-winded.

System is open vented according to Google(cold tank in loft....)

House: 3 bedroom bungalow with 1 bathroom + 1 en-suite. 9 radiators: Living, dining, kitchen, hall, 3x bedrooms, en-suite, bathroom.

Previous System when we bought house 1987: Potterton Ep2000 in utility room, Unknown Boiler in hall cupboard, Honeywell Thermostat in hall.
System now: Potterton Ep2, Worcester Bosch Greenstar r24i, Danfoss thermostat all in same locations.

In 2007 we had the boiler replaced along with all radiators except the living room one, system drained etc etc.
Few niggly problems with boiler initially but soon settled down.
We had intermittent small problems, mostly fixed in a timely manner by our local contractor(we have a monthly contract).
One small niggly problem persisted in that the boiler would not fire when it should have i.e. the house was getting bloody cold! I suspected the controller!?
In October 2013 a qualified electrician replaced the original Potterton Ep2000 with a wiring compatible Ep2.

The problem persists which is basically - the boiler does not always fire when the radiators get progressively colder and Mrs complains she is freezing. Hall thermostat set at 24 and even turning it to MAXIMUM does NOT cause the boiler to fire. Programmer CH light is ON, Hall Thermostat Green and Red lights are ON, Boiler Blue light is ON, Pump Green light is ON, but the boiler does not fire.

HOW I WORK AROUND IT AND TO DATE IT HAS ALWAYS WORKED:

1. Turn Programmer HW light(if it is on) by pressing the ADV button.
2. Switch Programmer OFF at the adjacent wall switch and count to 10.
3. Switch programmer ON which means it comes on with ONLY THE CH light ON.
4. Boiler fires almost immediately and Mrs soon happy and warm again.

Just had the annual boiler maintenance done. Mentioned problem to contract who reckoned the problem COULD be that the HW was set to come on along with the CH for the same length of time which is 06:15 - 09:30 and 16:00 - 21:30. Any other heating(ONLY) outwith those times initiated by press the Programmer ADV button.

Anyway, the problem persists and I am reluctant to go ahead with an expensive Evohome purchase/professional install(£740 for parts plus installation).

Regards

[top brake]

It's quite hard to follow your post but this sounds like a controls problem that would not be there when the existing controls are replaced by the evo

[donzo44]

Yes I do ramble on a bit sorry.

I sort of came to the same conclusion but wanted some reassurance before I commit to a large expense.

Thanks for your response.

Problem still persists. Youngest son arranged for engineer to call on Wednesday to have a look.

Will keep you posted but whatever happens I WILL go ahead with Evohome sooner rather than later

Regards

[The EVOHOME Shop]

Do you have a 3 port valve/Y Plan system? Either a component/wiring fault or the Worcester Greenstar Ri can be prone to 0-40v voltage feedback when fitted to S or Y Plan systems. I forget the name of the component you can use to cure this (top brake help me out here lol) but it is fitted between the live and neutral on the boiler and will prevent this.

Many thanks,

Richard

[donzo44]

Do you have a 3 port valve/Y Plan system? Either a component/wiring fault or the Worcester Greenstar Ri can be prone to 0-40v voltage feedback when fitted to S or Y Plan systems. I forget the name of the component you can use to cure this (top brake help me out here lol) but it is fitted between the live and neutral on the boiler and will prevent this.

Many thanks,

Richard

Thanks for your response Richard. I have no idea if I have such a system. 40 years in IT services but central heating is a black art to me. I will ask the engineer on Wednesday if I have such a system. Should I mention your fix to him or see what he comes up with?

Regards

Bryan

[top brake]

Do you have a 3 port valve/Y Plan system? Either a component/wiring fault or the Worcester Greenstar Ri can be prone to 0-40v voltage feedback when fitted to S or Y Plan systems. I forget the name of the component you can use to cure this (top brake help me out here lol) but it is fitted between the live and neutral on the boiler and will prevent this.

Many thanks,

Richard

Indeed this is a known issue with some boilers (I could bore you with the technical reasons behind it but rest assured this is not a problem with the controls as such) and a fix can be applied by fitting as capacitor as you mention. Call the Honeywell tech support line and mention boiler backfeed capacitor and someone from the tech team can help.

[donzo44]

Indeed this is a known issue with some boilers (I could bore you with the technical reasons behind it but rest assured this is not a problem with the controls as such) and a fix can be applied by fitting as capacitor as you mention. Call the Honeywell tech support line and mention boiler backfeed capacitor and someone from the tech team can help.

Fantastic help all round, thanks top brake. I will mention this to the engineer when he comes on Wednesday and keep you posted.

Regards

Bryan

[G4RHL]

Fantastic help all round, thanks top brake. I will mention this to the engineer when he comes on Wednesday and keep you posted.

Regards

Bryan

You won't regret installing Evohome. I don't think there is anything to match it and of course Honeywell have been doing systems for many decades.