Newly installed motorized valve not working

[brian62c]

Hi all,
Just had to replace both Potterton two-port MVs and Grundfos circulating pump in my quite old indirect system and while the central heating side of things is working, the hot water valve is not coming on at all when switched on at the programmer. The little orange light on top is not lighting up, leading me to suspect no power is getting through or, unlikely though it seems, the new item is duff. I wired both MVs in to the junction box exactly as per the old ones (took careful notes beforehand) and have even taken the offending MV's wires out and wired them back in again, just to check I hadn't done anything really stupid - but no joy.
If I pull the lever on the HW MV over to manual, there is a lot of gurgling, presumably from water flowing through the valve body (also both renewed) but still no orange light or motorized noises.
Any ideas very welcome. Oil boiler is an old Worcester Bosch, not condenser.

Cheers,

Brian

 

[Space cat]

The little orange light on top is not lighting up, leading me to suspect no power is getting through --

You need to confirm your suspicion one way or the other. Get yourself a meter (or borrow one) and find out. I'm afraid you won't get far trying to trace faults like this one if you don't have the means to check for the presence or absence of volts.

 

[brian62c]

Think I know where to find one of those .....

 

[45yearsagasman]

I assume the cylinder stat is calling?

 

[brian62c]

Hmmm, now you come to mention it ....
Not really sure. It's a fairly new Siemens RAM1 stat which replaced the old Potterton one. Presumably it was working before this project happened, as the old MV was functioning after a fashion (with a bit of persuasion at times) and we did have hot water from the boiler.
On re-reading the installation leaflet for the stat, it says it should be fitted to a pipe, whereas I put it directly on the cylinder, as the old one had been. Don't know if that would make a difference but the system was so up the creek before, it was hard to tell what was going on.
I'm going to check I've wired it in and assembled it correctly so thanks for the pointer, gasman.

 

[Space cat]

Directly on the cylinder is correct. (Ours is just below the level of the upper heating coil pipe; fitted by an excellent plumber as an emergency repair when our old cylinder died. ) I think you have a wiring problem.

 

[brian62c]

Thanks for the reassurance Spacecat.
I've now tried swapping the HW actuator with a spare one and still no orange light - so I'm thinking maybe I made a mistake when noting down how to wire in the new actuator.
My notes say the wires should go into the junction box as follows (moving down in order from the top terminal):

Brown wire - 2
Grey wire - 3
Purple - 4
Orange - 5

The 1st and 6th terminals are empty.

Is this correct?

I was pretty careful but the old eyes are not what they were and the terminals are pretty small

The CH side is absolutely fine, so I'm not totally incompetent

 

[45yearsagasman]

The numbers you give mean nothing unless you show the junction box and the other wires that are connected there.
Grey= perm live
Orange= switched live to operate boiler and possibly pump
Brown= live feed from cylinder stat
Purple?=are you sure its not the neutral?
You will need a meter to check.

 

[brian62c]

Right, I'll get a photo organised and post it. Some might say my 'purple' is blue but it's a very purplish-blue. Surely not an earth - even an amateur like me can recognise the green-and-yellow.
The junction box is a Honeywell, white plastic rectangular (horizontal orientation) about 6 inches by 3.
Pic to follow tomorrow.
Cheers.

 

[xr4x4]

Given what you know now, are you sure the old valves were at fault?

 

[brian62c]

Well Paul, good question but the valves themselves were definitely knackered (very rusted up) and one of the actuators definitely had given up the ghost. The other is probably still all right but while I was changing so much (the circ pump had gone too, along with the gate valves either side, and the immersion needed replacing) I thought I would start afresh with all new bits.
With the benefit of hindsight (it's a wonderful thing) if I had left the 'good' actuator still wired in, I would not now have this puzzle with the new one. We amateurs live and learn ... all the time.
If I could afford it, I'd just get a professional in to sort it for me - if I could find a decent one - but times is very hard and I can wield a spanner and screwdriver so perseverance will hopefully pay off.
I thought about just trying the top wire in the top terminal of the JB but am slightly afraid of doing more harm than good. Electrickery is not something I mess with lightly (no pun intended ).
I am still going to try and post a photo of the JB in case it sheds any light.
Cheers.

 

[brian62c]

Here are two views of the JB - the second one shows the wires coming in a bit better. Any views, anyone? Do my connections to the HW and CH terminals look correct?

Untitled

• brian62c
• 10 Apr 2012
• 1

 

[DBP]

You need to take the HTG valve wires and the mid posn/HW valve wires out and cut them down, if you put the cover on and wiggle the cables a little you could cause them to arc across each other. May burn out parts blow fuses etc...

 

[DBP]

Wheres the earth on the motorised valves?

 

[matt1e]

Hi brian from what you describe it looks to me like the programmer is faulty, a multimeter would be handy, but I'm willing to bet that if you take the blue wire out of the "Programmer" connector strip and connected in with the brown on the same strip then you will also get hotwater when ch is selected.
you could do with tidying that box up too, the valve cable cores req cutting down as per DPB's post above and the cables should be properly installed under the clamps.
I have seen worse though!

Wheres the earth on the motorised valves?

There isn't any on these actuators as they are double insulated

Matt