Strange Worcester Bosch issue (built in timer)

[Ab12]

Hi guys, after a bit of help...

Have just wired up my system with a hive and UFH setup with zone valves. All working great thanks to help from everyone here.

The problem I have found is that the system will only fire (when for example hive calls for heat), if the built in timer is plugged into the boiler and set to permanent on.

If I remove the timer from the boiler, unplug it, and try to get the hive to call for heat the boiler won't fire.

I'm not sure if aside from unplugging, I need to do something else....

Boiler is 35cdi combi

Greenstar CDi Classic Combi ErP Installation and Servicing Instructions | Worcester Bosch

central heating boilers, combi boilers, gas boilers, oil boilers, gas central heating, heating engineers, boiler installation, boiler repair

www.worcester-bosch.co.uk

Thanks for the help!

 

[stem]

That's quite normal. Usually those that give installation advice on here, if they know the boiler has a built in timeswitch will say that the heating will need to be set to be permanently 'on' at the timeswitch to allow the Hive to take full control.

The DT20 programmer that you have (I think that's what it looks like) would have been an optional 'add on' when the boiler was installed. It could be removed but usually you need the parts that were removed when it was installed to put back. Also the DT20 includes hot water control, so if you still use that part then it can't be removed.

 

[Ab12]

That's quite normal. Usually those that give installation advice on here, if they know the boiler has a built in timeswitch will say that the heating will need to be set to be permanently 'on' at the timeswitch to allow the Hive to take full control.

The DT20 programmer that you have (I think that's what it looks like) would have been an optional 'add on' when the boiler was installed. It could be removed but usually you need the parts that were removed when it was installed to put back. Also the DT20 includes hot water control, so if you still use that part then it can't be removed.

Thanks, so it seems to be a, leave it installed and set to permanently on for heating, and if used for HW also to permanently on.

Makes sense, thanks!

 

[MNW67]

and if used for HW also to permanently on.

I think you have a combi with a radiator zone and a UFH zone? Does the HW side of that timer control one of these zones?

So glad you got it working! It seemed like a massive job. What did you do about the boiler output from the UFH control centre?

 

[Ab12]

I think you have a combi with a radiator zone and a UFH zone? Does the HW side of that timer control one of these zones?

So glad you got it working! It seemed like a massive job. What did you do about the boiler output from the UFH control centre?

I have a combi boiler with a radiator zone and UFH zone correct! And thanks for the well wishes on getting it working. Glad I have!

I ended up getting the 3 port zone valve out and getting 2 dual ports in.

First one is my UFH, it's controlled by the UFH wiring centre, which is controlled by the salus roomstats in each downstairs room. They get the wiring centre to click on the pump and the UFH 2 port, which has a switched live back to the boiler (there's only one Lr on the boiler so it goes to that)

The other zone is my upstairs heating which is what the hive controls. Similar way.. hive gets a call, turns on/activates the valve, and the orange wire live switches the boiler on again in the Lr port.

Both apply to the CH side of things. I.e. they wont work unless I have that timer's (which is attached to my boiler) CH mode on permanently.

The HW side of that, not actually sure what it does....

In the hive I've left the HW connections alone as I won't have a system boiler and tank for a couple more years yet..

 

[Ab12]

Just coming back to my initial question. Not that it hugely matters. But still seems odd to me.

The manual for the programmer simply shows a plug and play installation, which would mean to me it's an unplug and go un-installation,

so.. still very strange to me that the Lr at 240v from the hive won't make the boiler fire unless the timer is plugged back in and on permanent on

Im simply curious as to why if anyone else has any input

Worcester DT20 Programmer Installation and Servicing Instructions | Worcester Bosch

central heating boilers, combi boilers, gas boilers, oil boilers, gas central heating, heating engineers, boiler installation, boiler repair

www.worcester-bosch.co.uk

 

[Ab12]

Looks like it's not working again.. argh