Boiler control - Can anyone make sense of this?

checjb · 1 Apr 2016 at 15:36

Hi folks,

I bought a Hive2 (with installation) because I read that my controller (a British Gas UP2) was a straight swap out, by simply taking off the front cover and installing the Hive controller onto the existing backing plate. Nice & easy.

Now, I've never been able to run my hot water and heating separately, even though the controler should allow it. It annoys me in summer but I've never got round to sorting it out. It's a fully pumped CH system with cylinder and room stats.

My problem is that when I opened up the cover, instead of six wires all neatly going into individual slots as per the Hive manual, I get this:

Any of you fine folks know what I'm looking at? Large image, btw.

checjb · 1 Apr 2016 at 16:18

Hi and thanks for the reply. Yes, I bought the dual channel version as my goal is to have the ability to use the HW and CH separately. It's always been a bug bear that I have to have the CW on in summer if I want some HW to wash up.

checjb · 1 Apr 2016 at 16:29

It seems to. I had to replace it about a year ago after the original was found to be inoperative due to a leak dripping on to it. TBH, I'm not really all that good with such systems and it's worked OK so I've kind of left it alone. The update to a Hive was the first 'real' work I've done on the CH system since I moved in.

checjb · 1 Apr 2016 at 17:06

OK. So, a few points to address.

I can use the HW on it's own but CH only works if I have HW on too (I got it the wrong way round in the post above). It's a Honeywell 4043H 2-port valve and it's set to AUTO. There is a slight resistance when I move it to MANUAl so I assume it working OK. Here it is in situ.

Here is a photo of the airing cupboard so you can see the layout. I think it's an S-plan but it's kind of odd. There is only one 2-port valve, the pump and the Magnaclean in the system.

checjb · 1 Apr 2016 at 17:27

Having dug around under the floor of the cupboard, here is another photo.

The black wire from the valve goes to that junction block where is is joined to the white white that then disappears down through the floor (preumably towards the controller on the ground floor). The other white wire you can see is separate and goes to the pump and also goes down through the floor. There seem to be no other wires heading down to the controller.

checjb · 1 Apr 2016 at 17:40

As you suggest Adam, there is only a single 2-port valve on the system. I suspect I have what you had. I suspect that I'll have to return the Hive as my system simply isn't up to making use of it.

The thing is the system works so until it dies I'm not keen on shelling out thousands for a new heating system.

checjb · 1 Apr 2016 at 17:42

Manic, the system is exactly as you described. It's a wired thermostat so that must be where the wires disappear to (it also makes sense it terms of the locations of things).

checjb · 1 Apr 2016 at 18:00

OK. Cheers for all the help and info, guys. I've called in a local heating plumber to provide quotes for a change in pipework and/or a combi upgrade.

I really appreciate all the quick help.

checjb · 13 Apr 2016 at 14:20

OK, so I thought I'd update this in the hopes it'll be useful to someone else. I got muy local plumber round and asked for advice/quotes. The upshot is:
* To convert it to an S-Plan (basically following the info FlyingFish provided above) including hiring a sparky to run a new line down from the new valve etc = £390.
* To fit a combi (inc new 22mm gas line from the meter, running hot and cold water feeds from across the kitchen to the boiler (in the utility room), running a condensate drain to the nearest drain, remove of header tanks, cylinder etc) with a wireless thermostat, 7 year warranty and new electrics = £3375.

Given that the boiler is very old (frankly, I'm amazed it's lasted this long) and I'd rather like to remove the opportunity for several hundred gallons of water to pour through my ceilings, we're getting a combi fitted.

Thanks for your help & advice everyone.