Sealed System - Draining and Refilling

I have a system boiler, S plan I think, one 2 port motorised valve to radiators and one to hot water coil in tank. Tank is in loft, boiler is in garage. It is now a sealed system (was changed from vented with tank when boiler was changed)
My motorised valve in the garage is goosed - it is passing (get warm radiators when only hot water on) and the plastic arm in the actuator has come adrift so limit is not being made when valve is closed and boiler remains on even although there is no demand from controls - guess it's a good job the valve is passing.

The valve is pretty old ACL Drayton and the actuator cannot be replaced - I have Drayton and Danfoss new valves spare.

I assume I drain down the system from the low points - think I have 2 under the floor and I have one in the garage.
I assume I need to the the HW motorised valve open for draining - easy with actuator off - but a general question - if you switch off boiler - can the controls then be used to open the motorised valves?

Also anything to look out for or take care with the 22mm fittings - is it OK just to remove valve and fit new valve - or do the olives need to be changed? Do you use PTFE tape on the fittings?

I have read about refilling and bleeding and getting a kit to top up with inhibitor. ONly thing I'm not clear on is where on the radiator to connect to - do you just remove the bleeder plug - add inhibitor - refit bleeder plug and fill and let inhibitor circulate.

I have 12 radiators - is 1 litre of inhibitor sufficient - all piping is copper - not microbore. Standard size.

Grateful for any advice.

 

OK - I have replaced the valve but still have some questions - I have fitted a Danfoss Valve and actuator - the actuator was a 4 wire one - compared to the ACL Drayton one I removed the actuator had no earth wire. Have run heating, and no leaks.

However, when out there this morning, I noticed that the boiler was still showing a demand, even when the heating and hot water were off. The motorised valve appears to be functioning correctly.

Controller is Potterton EP6002 - this was fitted onto the original EP2002 backplate.
Boiler is Ideal Logic System Logic 30+ boiler - this replaced an old potterton profile in Dec 2012.
There is a pressure relief/flow valve fitted between the supply and return headers at the boiler - this was added when the Ideal Logic boiler was fitted - and wish I knew about this as I would have fitted TRV's in the bathroom and shower room - I believe with this in the system I can fit TRV's to all rads in the house?

We originally had a solid fuel boiler, and thermostat in hall, until we got gas in the village - the thermostat was removed when the potterton profile was fitted.

There is a wiring junction box in the garage beside the boiler, and I have checked what has power with the different combinations. I measured voltage from each terminal to earth. The results are below. I think my wiring is incorrect possibly, the grey wire should not be on a permanent live? But my wiring is not so simple as this - HW valve is in the loft - I need to look at what's in loft and the backplate. Any ideas?
Hope the images from my google+ account work.

 

Thanks - makes sense. I don't think mine is wired as above. To start with I see nothing changing in the junction box in the garage when HW only is demanded.
There is a spare T&E cable in the junction box with end taped up - so I measured the volts on it to.
Power on 82 volts, HW only 82 volts, CH only 110 volts, CH+HW 110 volts - mystery to me?

The boiler SL Grey wire is wired into my terminal 1 which appears to be a permanent live - this will be why my boiler is on demand all the time the system is powered?
Photo of the junction box in garage - Now I don't know if the cables from the HW 4 way valve in the loft come here or not - in the loft it looks like normal T&E has been used for the Brown and orange wires - but would take a bit of work to figure out where they go and identify them? Would have been easy if I had seen a change of voltage when HW only was demanded?

Beginning to think this looks like a job for a specialist heating controls guy?
I suspect my room stat may have been removed and permanently bypassed. maybe if I took off the controller and checked the back plane wiring it may become clearer?

 

I think if I am getting someone in, I'd be as well fitting a new controls system - I wanted to get room stat fitted again, so might as well go for wifi model - but still easier with permanent power? I suspect the cable is still behind the wall - but my magic wand will detect a light switch cable there too. I also wanted to fit a weather compensation kit, but it needs to know when HW is demanded.
Maybe my thermosat on the tank has failed and is stuck on all the time also?

Would be simpler if the installer had marked on junction box which each port is!

 

Thanks - I know it is not wired correctly and I know if I got some time and assistance from my son who is an instrument tech we could easily figure it out. Access is not great in the loft, and I am think when I did my testing I should have had the cylinder stat set to lower than tank temp, and I wonder if the Motorised valve up there is also OK - just need to figure out the HW connections, and what they guy did with the roomstat 12 + years ago.

The firm who installed my boiler are no longer in business.

 

The only bad readings I got was on a cable that is not connected at the garage end - but is obviously still connected elsewhere - and as you say not very good! I can assure you that no "cowboy" builders have worked on this system, both big jobs were done by reputable local plumbing firms - although the one who fitted the last boiler are no longer in business. But obviously on the electrical side not too well!

 

I agree something is not right on that one cable - and the firm that installed the boiler had an electrician in doing all the wiring! My multimeter is correct!

 

So been up the loft this afternoon - the motorised valve up there is also goosed - same as one in garage - the plastic part underneath the metal arm that drives the valve has broken so valve not making limits. Could not be bothered draining down again today - job for my next day off on Friday!
Also did some quick measurements when up there. Orange showed 240 volts all the time.
HW Off (tank stat made I think) - Brown 0 volts
HW On (tank stat made I think) - Brown 240 volts
Hw On (Tank Stat not made - turned down) - Brown 0 volts.

I donj't know if this wiring in the loft is the same age as the house (28 years) - I don't think so - I remember all the heating controls going in when we installed gas, I'd guess 15 - 20 years ago when we got the supply in the village.
This is the HW valve wiring in the loft - and I know he has used black sleeving on an earth - when I saw a black wire and green/yellow connected I did not feel too well! And the cylinder stat wire I think goes down to the programmer - the EP6002 (was 2002) which I also suspect is a junction box).

Edited to add I think I'll get a proper junction box and fit that above insulation etc when I fit the new valve

Wiring junction box in garage (before I changed valve - the valve connections now in the top.)

 

I never checked the one in the loft as I would have had to remove the tape from the connector.
In the garage - yes it is live as it should be permanently.

If you notice the wire on the far left in the loft round junction box - not connected to earth - he has just cut the earth wire at the cable - maybe he run out of sleeving altogether!

 

New valves though are better - actuators can be changed!

 

New valve now fitted in the loft. Boiler is now going off when no demand from CH or HW. I'm not convinced although it's early yet, that the boiler is going off when the cylinder stat opens - need to watch it for a while. I'm also monitoring if I have a minor drip from one of the connections.

I bought some Corgi concentrated inhibitor, but have not put it in as noticed a sticker on the boiler saying Sentinel X100 had been used - and not sure it's wise to mix inhibitors? Anyone advise?
My fill line flexible hose also had developed a leak on the swaged connection so I have replaced the hose with a new one.

I'm also not sure the zone valve I removed was going fully open. I fitted a Drayton one to HW, and a Danfoss one to CH - I had bought them a while ago. In terms of valve (not actuator) the Danfoss seems a better built valve.

I've checked the junction box in the garage again - results are below - and still don't make sense to me. But I want to go further and identify each cable, but need to remove my programmer which is sealed with silicone (not grout) as it is tiled around. I am sure my controller is also used as a junction box for some wiring. I may leave this until after my next trip away. In the loft I connected the cable that was not connected to earth - to earth. The spare cable in the garage junction box now reads 0 volts.
It looks like I have 1 x Permanent live cables in the garage and the boiler SL is wired to this which is wrong. I need to identify what is turning connection 10 live and the other cable (connection 6&7). Will get to bottom of it.
I will keep the thread updated with my findings.