Hive Underfloor heating not working

[R7VSR]

Hi everyone,

I'm looking for some advice.

I replaced the “invisible heat” thermostats and wiring centre for a wet underfloor heating with Hive.

The underfloor heating has 4 zones with a thermostat on each zone.

The engineer installed one hive receiver for each zone. Four in total.

So far so good. It all seems to be wired correctly and working fine. However, when you select a zone to heat all the zones go on. Basically an on/off switch. I cannot warm up zones individually.

I consulted with other engineers to see what can be done. Apparently Hive doesnt work with this type of underfloor heating systems. The engineer suggested adding relays that would open the valves or pump. Not sure about the technical details and the cost, or how effective that would be.

The other options is to replace it with other alternatives like heatmiser, that seems to work straight out of the box. Waiting for a quotation to compare the impact.

Before taking any steps I wanted to get a second opinion.

Is there anyone one in this forum that may have some ideas what could be wrong?

I attached some pictures of the manifolds and hive installation for reference.



I appreciate any advice.

 

[CBW]

Were they thermostats or heat sensors? If the latter, then it might be correct that standard thermostats do not work.

 

[R7VSR]

Thermostats

 

[CBW]

Then each Hive needs to correspond with each zone, which I suspect isn’t happening, which would possibly be the wiring up of them.

 

[ericmark]

The engineer suggested adding relays that would open the valves or pump.

Yes that is normal a unit like this is used which is a bank of relays, the same applies with normal heating when split into zones each zone valve has a micro switch built in which acts as a relay.

You need to control two things, the solenoid and the boiler independent, with hive the normal is to have wifi connection to zones and hard wired to boiler, so the TRV controls the zone and wall thermostat controls the boiler.

Arrow shows the UFH equivalent of the TRV, but unlike the TRV they are hard wired.

I am an electrician not a heating engineer, so not fully conversant on how UFH is controlled, the main advantage of UFH is the water temperature can be much lower, the circulating water does not normally exceed 30°C which means with heat pumps it works better, and with condensating boilers it can also work better as return water cooler in theory anyway.

But disadvantage is response time, it takes a long time to both heat and cool, so not really compatible with a geofencing system, whole idea of internet connected heating systems is as you approach home it automatically turns on heating, so heating needs a fast response time, so normally UFH sets a back ground heat, and radiators boost the temperature as you approach home.

It is the same with standard heating, to heat from 0°C to 20°C takes too long, anyway risk of freezing, so we set two temperatures eco at say 16°C and comfort at 20°C and the room is kept at 16°C until it detects your phone, so it boosts temperature 4°C.

It seems this is missing in your system, you really need a heating engineer to install a heating system, to become an engineer means over level 3 training, i.e. University, so proper engineers are not cheap, but when fitting a complex system you need to have some one who knows what they are doing.

 

[ericmark]

Sorry just a thought, I know hive can have two zones CH and DHW, and in gravity mode one relay in the hive works the boiler and other works the pump, so same arrangement with one relay to boiler and one to UFH solenoid may be possible?

Wait in case that is done, I may have over looked this method.

 

[CBW]

Sorry just a thought, I know hive can have two zones CH and DHW, and in gravity

If dual channel have been used. I suspect that x3 single channel and one dual or all singles?

 

[Higgy28]

Deleted.

 

[stem]

If you originally had 4 separate standard room thermostats and the system worked, then I can't think of any reason why replacing them with 4 Hives wouldn't work. From an electrical point of view a thermostat is only an on/off switch and so is the Hive. [It's the software that tells the Hive when to switch on/off that is the clever bit] So electrically, you are simply swapping one identical item for another identical item.

When you turn just one zone on, do all of the receiver lights come on?

What happens if you start with all of the zones off and then just switch one receiver on manually using the button on the front?

Having said that, I'm not familiar with an “invisible heat” make of thermostat, so it may be a non standard device. Do you have any details of them?

If dual channel have been used. I suspect that x3 single channel and one dual or all singles?

Three singles and one dual according to the OP's photo....

....if the dual is for one heating zone and hot water, I wonder what this is this doing?

 

[Higgy28]

Are all 4 receivers linked up to the same wireless thermostat by mistake?

 

[stem]

Hmmm, that's what I was wondering, when I asked.

What happens if you start with all of the zones off and then just switch one receiver on manually using the button on the front?

That would help determine if it's a wiring issue or not.

Hive can do 6 Zones maximum, so the number of zones isn't an issue.

 

[CBW]

It would be interesting to see the wiring behind those receivers.

 

[Poolspringe51]

I think I may have the same problem in reverse..... I can operate my rads with Hive without the Underfloor heating coming on but not the other way round. I've turned the Hive to OFF for the rads and the UFH to manual and ON (with a second Hive thermostat - Hive Active Heating Thermostat V3) and the rads upstairs get so hot I can't touch them and I can't stop them coming on. The heating engineer has looked at the wiring (he installed the new UFH in the new kitchen) and has now installed a non return valve but it's made no difference. Any suggestions?