Hive Wiring to Replace Watts BT-WR02-HC RF Receiver for Underfloor heating

[vanr]

I currently have a Polypipe Single Zone Master Unit (PB1ZM) connected to Watts Receiver and Thermostat to control my underfloor heating. The RF Receiver is playing up so going to replace this with a HIVE Active Heating dual channel setup, which will also allow me to replace the Honeywell STC94000 heating programmer that controls the hot water.

I am good with wiring the Hot water over to the Hive RF Receiver, but have a question on the Under floor heating:


The Polypipe Single Zone Master Unit (PB1ZM) is wired to the Watts RF Receiver as:
T1 --> 1
T2 --> C

in oder to Wire the Polypipe Single Zone Master Unit (PB1ZM) to the Hive RF Receiver should

T1 --> Hive 4: Heating on?
T2 --> Hive 2: heating off? or is this redundant and not needed?

The Watts Receiver I believe is BT-WR02-HC RF, although could not find manual with same circuit diagram and only thing on the back is:

For completes Polypipe Single Zone Master Unit (PB1ZM) standard wiring instructions

 

[Deleted member 267285]

C(common) wouldn’t be needed on a dual channel

 

[vanr]

Thank you for taking the time to respond.


I have now wired in the Hive (T1 --> Hive 4: Heating on), but when pressing for heat on the hive receiver to test it, the boiler is not coming on, nothing happens not event the clicking noise as described below. Have put the wiring it back as it was for now it took a while for the old Watts Receiver to come to live, that I thought something was broken. Am now thinking that something is up with the Polypipe Single Zone Master Unit (PB1ZM) as the clicking on/off noise/sound seems to be coming from it rather than the Watts RF receiver as I originally thought, when trying to call for heat the valve light goes on/off repeatedly along with the clicking on/off noise/sound (Suspect the relay switch). There are times it stays on and works but more frequently now it does not.

Interestingly when connected to the Hive RF Receiver, nothing happens, don't even get the clicking on/off noise/sound, no led; s light up, other than the power led (not showing photo)

May have to look at replacing the Polypipe Single Zone Master Unit (PB1ZM) unit?

 

[vanr]

Replaced the Polypipe Single Zone Master Unit (PB1ZM) today and connected (T1 --> Hive 4: Heating on), but no joy, seems T1 has a low voltage on it.

So going to call an engineer to sort out will post once I have the solution.

 

[stem]

You can see that I have highlighted in the copy of the diagram that you posted that it shows a voltage free thermostat connection.

Whilst Hive Single Channel does have a voltage free contact, Hive Dual channel doesn't, it only has a 230V output. If the Polypipe Single Zone Master Unit (PB1ZM) requires a 230V signal that's fine, and the manual should tell you which of the two thermostat terminals T1 or T2 to connect it to. If on the other hand it doesn't accept 230V then you may have damaged it.

 

[vanr]

Thanks Stem for your reply. I have now had it sorted. Indeed the culprit was the Watts RF Receiver. Connecting Polypipe Single Zone Master Unit (PB1ZM) (T2 --> Hive 4: Heating on) fixed the problem.

I then had one additional problem in that when using Hive to switch the heating on it also turned on the hot water. I had setup Hive as Gravity Fed (so blue light instead of green) as I do have a gravity fed hot water system, however setting this back to part-pumped fixed that problem and now all is in order .

 

[Echo the husky]

Do you really have a gravity hot water system? Most of these systems have been removed years ago due to the huge inefficiency. If you can run the radiators without the hot water being on at the same like you have a fully pumped system, not gravity.

 

[stem]

I then had one additional problem in that when using Hive to switch the heating on it also turned on the hot water. I had setup Hive as Gravity Fed (so blue light instead of green) as I do have a gravity fed hot water system, however setting this back to part-pumped fixed that problem and now all is in order .

That's what the gravity setting does. But as per @Echo the husky that's only used for extremely antiquated systems that probably were installed 40 to 50 years ago and that don't have motorised valves to provide separate control of the heating and hot water systems.

Don't confuse 'gravity fed' with 'gravity circulation' they are completely different things.

Gravity Fed means that there is a cold water storage tank in the loft that keeps the system filled with water. Unless really ancient, these systems are still generally fully pumped and have motorised valves. In this instance Hive should not be set to 'gravity'

Gravity Circulation this is where the hot water is heated by natural gravity circulation between the boiler and the hot water cylinder, in that hot water rises and cooler water falls. The hot water part is not pumped and in this case the Hive should be set to 'gravity'.

Unfortunately the Hive guide incorrectly uses 'Gravity fed' to describe 'gravity circulation' and has caused a lot of confusion as a result. Hive do correctly call it 'part-pumped' in that the central heating is pumped but the hot water isn't.