Honewell HR92 Problems

[dovharris]

Hi, I've just had 4 new HR92s fitted, to replace normal TRVs.
I thought I'd start with 4 and see how it goes.
So the controller is only controlling 4 HR92s.
Everything is working as it should - the valves are displaying the set points, and the radiators heat the room to the set point and then turn off as they should.
So here's my problem.
When the system comes on (via a normal timer, up by the boiler), 3 of the 4 valves open as they should and heat the room as they should.
But one of them doesn't. It stays shut until I remove the head, and replace to force a recalibrate. Then it works fine.
At first I thought I had a dodgy HR92.
But it's now happened to a second one?
They are all bound, and communicating at full
Does anyone have any ideas?
If more information is required, please let me know.
Thanks in advance, Dave

[DBMandrake]

When you say it "stays shut" how are you determining that ? Do you just mean that the radiator doesn't heat up ? Or are you lifting the HR92 off and then finding you can manually turn the black wheel back a long way and then the radiator gets hot ?

The way to check the valve pin position on an HR92 is to hold the button for a few seconds until the menu appears, go to option 10 and change it to 1. This will report the valve pin position. Zero means fully pushed down (closed) and 100 means fully up, (open) with numbers in between being partial flow. What does it report when you think it is closed ? Typically a valve will start flowing at about 30 reported and be fully flowing by about 70.

Also what is the measured room temperature and the set point at the time you think the valve should be opening ? Are you sure the room isn't already near up to temperature ?

I think you also need to describe your system a bit more - you say you still have a "normal timer" - what does that mean ? Is the timer wired in series with a BDR91 ? Or is it wired in series with a room stat as before ?

If so is the Evohome not controlling boiler demand in any way ? Sounds like you might have a frankensystem there so a description of how it is wired up and what is controlling what would be helpful.

[dovharris]

Dear DBMandrake,
Thanks for your very full and comprehensive post. I'll try to answer your questions

Firsly I'll describe the system a bit more.
It's a large house with 12 rads on 3 levels.
We've just had the boiler (Worcester Greenstar 24Ri) and a 4 rads replaced (they were >40 yrs old), and I wanted more control over the temperatures on the 3 floors.
Our heating man (who is a local fitter in SE London) suggested regular TRVs everywhere - he's not a fan of conntrolled systems.
So we compromised - a frankensystem as you say.
We have TRVs everywhere except 4 of them have been replaced with HR92s and the controller (ATC928). The wireless relay box (BDR91) is not being used.
I figure that if these HR92s work well, and I want to expand my controlled system, I can.
So at the moment, I sit at my desk and control 4 from 12 rads without moving! An expensive toy, some would say.

Secondly, to your specific questions.
Option 10 gave a reading of 100. Despite the room temperature showing 22, the set point showing 21.5, and the room being 18!
I have all the 4 HP controlled rads, option 7 set to 1 for room temperature, and an expensive room thermometer showing the correct room temperature. Also, the room feels cold!

Would a rebind help? These were bound by the local fitter, and it's the first Honeywell system he's fitted.
One further thing to note - the controller display all the readings accurately; ie. exactly the same as each individual HR92 displays.
Cheers, Dave