HR92 often opens only for a few percent, boiler doesn't fire

[BrechtM]

Hi everyone,
I'm encountering an issue with one of your HR92's. When changing the setpoint to a higher temperature, the valve opens but often only for a very small amount (02 - 07 percent). It stays like this for hours. In those cases, it does not trigger heating demand.
On other times, it opens to 100% and triggers heating demand.

I'm wondering if this is still some learning phase as I installed them a couple of weeks ago. However, I don't understand why it would open for only a couple of percents and not trigger the boiler. Not much to learn in that case...

I have replaced batteries, re-paired and reseated the TVR with the valve fully opened (CYCL runs fine after installing TVR)

Thanks

[Richard]

What valve bodies are they fitted to?

[screamagain]

Hi BrechtM

I have the same issue.

So should an HR92 be fitted to a specific valve body? If so I’m going to buy 8 and sort this once and for all.

Glad you raised the topic.

Stephen

[The Heating Consultant]

Some radiator valves have a rubber plunger on the valve actuator and this compresses. This means the HR91/HR92 can open 10-15% and still there is no flow through the radiator valve. Higher quality radiator valves don't have this issue. If the radiators valves are old, I would also consider changing them out if you have this issue.

[Richard]

Our advice is to change any radiator valves that are over 15 years old. We sell Honeywell valves here - https://thesmartthermostatshop.co.uk/pr ... well-home/

Alternatively we sell IMI Eclipse valves which have patented pressure independent technology, and guarantee the correct flow rate goes through each radiator once they are set (saves hours trying to balance heating systems correctly) - https://mwphs.co.uk/product/imi-eclipse ... 690-61800/