OpenTherm control behaviour

[rotor]

I am a bit confused. The way that this reads is the Ideal buys its boiler PCBs from Honeywell. It seems strange to me that if one supplier is manufacturing both the opentherm bridge and the PCB that this type of issue has arisen.

Just looking at all of Honeywell's thermostat products, I get the impression that it's a very disjointed company.

[HenGus]

Just looking at all of Honeywell's thermostat products, I get the impression that it's a very disjointed company.

You might be right, but I would expect them to test their PCBs with their very own bridge at the very least. Or conversely, test their bridge with the PCBs that they manufacture given that the issue is that Evohome with an Opentherm bridge appears to be overriding boiler PCB settings.

It does beg the question 'is Honeywell 100% confident that the bridge is not the issue'? I ask because having had one installed, I have a vested interest.

[paulockenden]

Maybe "Honeywell have provided us with updated boards" was a typo?

P.

[kimber.kimber]

Maybe "Honeywell have provided us with updated boards" was a typo?

P.

Not from me! I'm assuming that they have been working with Honeywell with regards to the logic on the board, or something similar. I would be surprised if Ideal were sourcing their control boards from Honeywell, however that said they are a massive company, making everything from turbochargers to heating controls, so who knows!

Like I said, I'm going to do a little more digging, but also don't want to upset the apple cart.

[kimber.kimber]

Actually it might not have been a typo... Maybe one arm of Honeywell doesn't talk to the other...

http://ecc.emea.honeywell.com/oem/combustion/residential_heating/boilers/boiler_electronics.htm

[The EVOHOME Shop]

You might be right, but I would expect them to test their PCBs with their very own bridge at the very least. Or conversely, test their bridge with the PCBs that they manufacture given that the issue is that Evohome with an Opentherm bridge appears to be overriding boiler PCB settings.

It does beg the question 'is Honeywell 100% confident that the bridge is not the issue'? I ask because having had one installed, I have a vested interest.

Honeywell is a vast company with many different departments. Not easy to navigate internally I would imagine.

I am personally confident there is nothing wrong with the OpenTherm Bridge Hengus.

After much testing and monitoring of OpenTherm systems (including the R8810) over the past week, I have discovered ways of ensuring the evohome system works with OpenTherm and Intergas boilers - something thought not possible in the past. I now have 3 evohome systems working with Intergas and all are multi zone.

What boiler was the PCB issue with? What exactly was happening?

[Rameses]

Hengus - do you have a call logged with us? If so can I get the case # and you DM me it please

[HenGus]

Hengus - do you have a call logged with us? If so can I get the case # and you DM me it please

No case open at the moment. My Atag IS24 is connected to Evohome via an OT bridge. HW control is absolutely fine (ie; the boiler is limited to the max flow temperature set in the boiler profile.) My slight concern, based on about 3 weeks of CH in early April under OT control, is that the boiler is very slow to get into condensing mode which rather defeats the object of having a modern efficient boiler. Other posters have suggested that other OT controls such as Remeha effectively start the boiler in a condensing mode. All my installer will say is that what I am observing is down to Honeywell/Evohome's 'fuzzy logic'. I should add that I deliberately set up HW heating outwith the CH On time to ensure that the boiler was just providing CH.

Having invested some £000s of in a new boiler, I am obviously keen to know with as much certainty as possible that Evohome OT control will not damage the boiler or reduce its useful life.

[Rameses]

Need you to log a call so as to get you injected into the 'process' - posting here will not initiate that.

Once a call is logged all sorts of good things happen - your system can be monitored, people get aligned, etc

[HenGus]

Need you to log a call so as to get you injected into the 'process' - posting here will not initiate that.

Once a call is logged all sorts of good things happen - your system can be monitored, people get aligned, etc

Thanks. Will do.

[StephenC]

I have passed on to the team. And Opentherm are in the mix as well.

Just seen this @Rameses.

I've had to revert back to BDR91 due to excessive temps. It's just not possible in this weather to have the OpenTherm R8810 controlling my boiler. In the depths of winter, then of course the issue is less pronounced. I still have the R8810 OT bridge, so can put in back into control the boiler if needed.

I did have a call logged previously as well to add to this (case ref: 14575585) - does this help as there was monitoring of my device and OT bridge earlier in the year?

Stephen

[fergie]

What boiler do you have Stephen?

[StephenC]

What boiler do you have Stephen?

Hi,

I have a Viessmann Vitodens 111-W Storage Combi 35KW (installed 2014 - and has rotary DHW and CH temp controls. Newer models have LCD screen with digital controls)

http://www.viessmann.com/vires/product_documents/5618689VSA00001_1.PDF

See here for my journey (So far) with Opentherm:

http://www.wordpress-1219309-4387497.cloudwaysapps.com/vbulletin/showthread.php?5133-Opentherm-EvoHome-Viessmann-111-W-overshoots

Stephen

[kimber.kimber]

So today Ideal have been out and replace the PCB in the boiler. Now the knob on the front controls the temperature of the flow and it isn’t over ridden to max whenever there is a heat demand. Also for the first time, I’ve seen boiler efficiency over 50%. This is a measure of how long the boiler is in condensing mode.

Still need to see how it gets on with modulating the temps. But for now it definitely seems like an improvement.

[DBMandrake]

Didn't take long did it...