Help with Evohome / Opentherm / Intergas

[The EVOHOME Shop]

Just to confirm, my findings have now been confirmed by Honeywell and there is no issue with either evohome or Intergas boilers.

[fergie]

So how does everyone with intergas get their multizone evohome working correctly via OT?

And is it specific to one boiler or whole range?

[The EVOHOME Shop]

Just bind as normal with an OpenTherm Bridge - all binding tests (including pairing the way stated in the book) come back as working fine. No special methods are required.

The Intergas OpenTherm protocol is the same throughout the Intergas range so shouldn't matter what the boiler is.

[blowlamp]

Just bind as normal with an OpenTherm Bridge - all binding tests (including pairing the way stated in the book) come back as working fine. No special methods are required.

The Intergas OpenTherm protocol is the same throughout the Intergas range so shouldn't matter what the boiler is.

So what is the cause of the Evohome/Intergas 'issue' - or are you saying that the cause of the perceived absence of modulation that's been reported (under multiple zones), has simply been Evohome running at 100% because of demand from a zone outside of the 1.5C proportional band? In other words, a non-issue?

[paulockenden]

So what was the problem that several people reported? What were they doing wrong?

The reported problem wasn't with the binding - it was the boiler's response times when the heat demand changed rapidly. I think.

P.

[bruce_miranda]

Just to confirm, my findings have now been confirmed by Honeywell and there is no issue with either evohome or Intergas boilers.

So is there an issue or isn't there an issue. In this thread itself, there is suggestions of both.

[HenGus]

So is there an issue or isn't there an issue. In this thread itself, there is suggestions of both.

There clearly was a perceived issue as Richard and Dan said so on the Evohomeshop Home forum:

Quote: Evohome will ignore the weather sensor.

At the moment you're better off using the weather sensor and a standard BDR. Unquote

Quote Thanks Dan for the advice! 8-) Are Intergas still having issues with the OpenTherm protocols and evohome multi zoning? Unquote (October 2017)

AND Intergas Tech Support confirmed in writing to me that there was an issue that the guys in The Netherlands were investigating.

So, ten months on, Richard and Dan have now shown what was thought to be an issue is no longer an issue, but we lesser informed mortals are non the wiser as to what the original concern was, and why the situation has now changed. Hardly, a ringing endorsement of Evohome and Intergas (and Intergas' UK Technical Support team).

Have I just imagined all this?

[Dan_Robinson]

No you haven't imagined it but you are misinterpreting things slightly.

First of all is the weather sensor thing is a second issue and not a problem, only it's a featureset (or lack of).

Perhaps Richard should have written "there is no longer an issue".

[HenGus]

I need to lie down.

[The EVOHOME Shop]

There clearly was a perceived issue as Richard and Dan said so on the Evohomeshop Home forum:

Quote: Evohome will ignore the weather sensor.

At the moment you're better off using the weather sensor and a standard BDR. Unquote

Quote Thanks Dan for the advice! 8-) Are Intergas still having issues with the OpenTherm protocols and evohome multi zoning? Unquote (October 2017)

AND Intergas Tech Support confirmed in writing to me that there was an issue that the guys in The Netherlands were investigating.

So, ten months on, Richard and Dan have now shown what was thought to be an issue is no longer an issue, but we lesser informed mortals are non the wiser as to what the original concern was, and why the situation has now changed. Hardly, a ringing endorsement of Evohome and Intergas (and Intergas' UK Technical Support team).

Have I just imagined all this?

The evohome Controller is on software version 7.01, so there have been several software changes that I knew nothing about (until one of my recent evohome Controllers updated before my very eyes when I connected it to Wi-Fi). I only got my Intergas boilers (here at the new unit) up and running a few weeks ago and hence I have just recently tested the 'incompatibility'. Before this I had been relying on installers for information about the Intergas 'issue'.

Honeywell were here with me Monday and we tested everything to absolute death - there is no issue. This may have been an update to evohome, but this would be mere speculation as I don't work for Honeywell. I really don't know what the previous issue was, as I never saw the issue first hand that had been reported. The fact is the problem (if there was a problem before?) is no longer a problem. My testing started with a MK1 greyscale evohome and Intergas and there was zero issue with this device. I moved onto MK3 and still I could find no issue.

My personal feeling is that the information on how evohome is supposed to respond to OpenTherm had never been confirmed by Honeywell (no one had asked either), so those 'testing' it were really only guessing and assuming it works similar to TPI control (1.5 degrees proportional band, etc) - it doesn't.

I will be honest, there are things I thought I knew about evohome that I didn't know at all and now I know these things it is now hard for me not to get evohome to modulate the boilers control setpoint. For instance, I know if I set the demand 1.5 degrees over actual temperature with OpenTherm, evohome will likely go to maximum. If i set a HR92 to 19.5 in a room showing 19, then it will set the control setpoint to maybe 50? It's quite logical how it works, but means we need to adjust our thinking as installers when fitting modulating controls verses ON/OFF or TPI control and re-learn things we have been teaching customers such as 'night setback' temps (maybe making these a little smaller).

Anyway, no doubt there will be more questioning so here's my thought for the day...

"Don't be surprised that your car will keep accelerating towards a wall if you keep pressing the accelerator pedal." - Richard Burrows, The EVOHOME/INTERGAS Shop, August 2017.

[The EVOHOME Shop]

I need to lie down.

This is something we both agree on...

[mylesm]

Thats Great so to upgrade an existing Evohome System which has a BDR Boiler relay and only HR92s no HW everything works now,
DO I just replace the Boiler Demand Relay with an opentherm bridge and wire it into Terminals 11 & 12 on X4 of intergas boiler

Thx Mylesm

[HenGus]

My personal feeling is that the information on how evohome is supposed to respond to OpenTherm had never been confirmed by Honeywell (no one had asked either), so those 'testing' it were really only guessing and assuming it works similar to TPI control (1.5 degrees proportional band, etc) - it doesn't.

I will be honest, there are things I thought I knew about evohome that I didn't know at all and now I know these things it is now hard for me not to get evohome to modulate the boilers control setpoint. For instance, I know if I set the demand 1.5 degrees over actual temperature with OpenTherm, evohome will likely go to maximum. If i set a HR92 to 19.5 in a room showing 19, then it will set the control setpoint to maybe 50? It's quite logical how it works, but means we need to adjust our thinking as installers when fitting modulating controls verses ON/OFF or TPI control and re-learn things we have been teaching customers such as 'night setback' temps (maybe making these a little smaller).

:

I have been asking for Honeywell to provide information on normal Evohome/Opentherm operation for the past 6 months. Given that the very essence of Evohome is multi-zoning then it would seem that cranking the boiler up to max flow temperature,when any zone is outwith the 1.5C difference, runs counter to what Opentherm is designed to achieve.

Exam question: Would better boiler efficiency be achieved with standard TRVs or single zone control (boiler operating under Opentherm control) than with Evohome/Opentherm multi-zoning.? Discuss

[The EVOHOME Shop]

Thats Great so to upgrade an existing Evohome System which has a BDR Boiler relay and only HR92s no HW everything works now,
DO I just replace the Boiler Demand Relay with an opentherm bridge and wire it into Terminals 11 & 12 on X4 of intergas boiler

Thx Mylesm

Indeed, then follow the binding instructions in the evohome Installation Guide for binding the OpenTherm bridge...

[Dan_Robinson]

I have been asking for Honeywell to provide information on normal Evohome/Opentherm operation for the past 6 months. Given that the very essence of Evohome is multi-zoning then it would seem that cranking the boiler up to max flow temperature,when any zone is outwith the 1.5C difference, runs counter to what Opentherm is designed to achieve.

Exam question: Would better boiler efficiency be achieved with standard TRVs or single zone control (boiler operating under Opentherm control) than with Evohome/Opentherm multi-zoning.? Discuss

I think a 1 degree control bandwidth is far too small. With modulating controls it need to be 2 maybe 3 degrees.