Further to my earlier post re: changing my girlfriends cylinder. The current system is pumped but there are no controls apart from a timer so it's either hot water and heating or nothing. Whilst I have the system drained to replace the leaking cylinder I plan to convert it to a crude S plan by fitting a zone valve on the feed to the heating circuit, problem is I won't have time to do the wiring etc because I'm going away for a while. Are zone valves normally open when un-powered or do they need power to reamin open? Thanks chaps, as always your help is greatly appreciated.
zone valves are closed and need power to open, your main problem will be whether there are any rads taken off the circs before the cylinder or it won't work the rule is this, from boiler first tee vent, second tee, cold feed, third tee cylinder, and on the return last tee before boiler is the cylinder, hope this is usefull
Thanks Tom that's great, I will take a picture a bit later and post it on photobucket. I did have a quick look last night and it looked like it would work but i'm not sure!
Took a picture but can't get in online! Can confirm that the order of things is as you said Tom and there aren't any radiators teed off before the cylinder. I think my main problem is that the existing cylinder is only 1030 mm high by 370mm wide and there isn't any room for a wider one in the cupboard.
You would be wiser to leave things as they are then do a proper conversion later when you have the time.
Thanks Skip but what do you mean? Is the cylider size the problem or do you just think I shouldn't fit a zone valve until I have time to wire it up?
OK.. I won't, must admit I was wondering how I was going to keep it open to allow the heating to work until I'd got it wired.
http://www.flickr.com/photos/55035994@N06/5102230293/ Managed to get the picture online. The pipe nearest the door is the flow to the rads, I intend to fit the zone valve between the two compression couplings you can see. The vent is the horizontal piece of 22 at the bottom and the feed from the FE vessel is T'd in above it. Just in case you're wondering, the bent piece of 15 you can see above the pump terminates just out of view, it is an air vent.
nor, i thought u was going for 2... why dont you fit 2 honeywell valves & a bypass ? u can open the honeywell ones with a lever till u get time to wire it in .
the t above the pump looks ideal to swap and fit a 3port to make it a y plan , whatever you do fit gate valves either side to allow easy maintenance later, as said you can manually lock open motorised valves