Worcester Bosch 240 with Hive v1 - no hot water without CH on

[G7COG]

Evening,

I've an old WB240 boiler has been working ok for my needs up but now I am looking for more control over it.

When I moved into the property it had a British Gas UT2 single channel controller attached. I believe this is the same as the Drayton product just rebadged. I have never bothered with a heating schedule so the UT2 has always been set to 'On' and then the switch on the front of the boiler left on Water unless I wanted the heating on when I would flip the switch over to Water and Heating. There is no thermostat connected to this system.

I saw Screwfix had the Hive V1 on sale today so decided to grab one.

It's installed and all connected up however I've realised that I can't do what I was hoping to do with the current install setup. Basically now the Hive controller is in place it doesn't matter whether the boiler switch is on Water or Water and heating as I won't get any hot water unless the Hive unit is trying to power up the heating.

Is there a way to rewire things so that any demand for hot water will always be met whilst allowing the Hive control unit to turn the heating on as and when required?

I've looked at the wiring diagram for the 240 and checked the board and can see that there is a part of the control board for a room stat to be wired in which currently has a small loop of wire connecting 2 pins.

Is what I'm looking to do possible as I would have thought it was a fairly common request that people would want to be able to do with a simple combi boiler setup.

Any help would be greatly appreciated. I did do a search but couldn't find a similar thread to work from so apologies if I've missed one.

cheers,

G

 

[ollski]

Single channel Hive connects to your room stat connections and permanent live / neutral. Not too sure how you've wired it in

 

[G7COG]

Hi,

It is wired in exactly the same as the UT2 was previously as the backplate is compatible. Literally unclipped the UT2 and clipped on the Hive.

Thinking about it now it would appear that the UT2 was literally turning the mains on and off to control the CH coming on and off which is going to stop the boiler firing for water if it isn't giving power. The Hive will be replicating this.

Should it have been wired like that as surely dropping the power off when turning the heating off will stop any pumps running whilst heat is dissipated at the end of a cycle etc?

I've attached pics of the backplate and the cable coming into the boiler.

I think what you are saying is that I will need to run another cable from the backplate to the thermostat point on the circuit board.

 

[G7COG]

I've just found another manual which may be of use.

I would think that wiring the Hive receiver up to control the switch would enable me to have permanent hot water whilst the Hive knocks the heating on and off as required with no connections being made to the room thermostat connections on the circuit board.

Advice greatly appreciated.

 

[DP]

Hive is just a thermostat, nothing more nothing less.

I would be hooking it to the the boiler in place of the loop at 1 and 2 on roomstat termination in your picture

 

[G7COG]

Thanks.

So how would that correspond to the backplate as per the Hive diagram and the links on the boiler?

Permanent Live, neutral and Earth wired across to their current locations on the main board then Heating on (NO) to the 1 at the room stat location having removed the loop? Would I also run the Heating off (NC) to point 2 on room stat at the board?

So if that is correct I would leave the main boiler switch on Heat and Water so that water is available and then the Hive would turn the CH on and off as required?

 

[DP]

You use C and NO contacts for where the loop is

 

[G7COG]

Thanks guys. Working as it should now. Just needed the one wire from 3 on backplate to 2 are x4 on the boiler. Happy days.

 

[DP]

Thanks guys. Working as it should now. Just needed the one wire from 3 on backplate to 2 are x4 on the boiler. Happy days.

Where does C of backplate go?

Remember, condition at 1 of X4 goes to 2 of same block with that wire link
The link is removed with that action taken over by 1 and 2 of the back plate
Your boiler may well be working but it is not the voltage at 1 of X4 that operates the boiler but voltage from elsewhere (L terminal of backplate?).

Looked at the schematic and your backplate. I hope you have correct fuses in place as you have bypassed the 2 amp fuse that protects the pcb during CH demand