Plumbing

Today was a plumbing day. I don't mind plumbing, but it can be quite stressful. The object today was to add some long needed control to the heating system in the manse. I've talked to various folk about it before, and I hope the deacons don't mind, but the impending increases in gas prices has been a strong encouragement to get this done.

It's been over 20 years since I was actively involved in heating system control. it was part of my job as a research scientist with British Gas to know my way around a wiring diagram and more. So today's task, whilst not straightforward, was familiar ground to a certain degree.

It was actually Anne's idea to get cracking and do the job, so I enlisted her help as we set out to shop for the component parts for the job.

We went to Screwfix for most bits, Plumb Center for one part and Focus Do it All for some 6 amp cable. We needed a 28mm 2-port zone valve for the hot water circuit and Plumb Center was the easiest place to go for this. It's 28mm because the system in gravity fed. This means that there is no pump for the hot water part of the heating system. The radiators are pumped and the boiler is an uncomplicated bit of machinery.

The other parts we needed were a cylinder thermostat and a room thermostat. We chose a simple cylinder stat, but, because of the problems with running wires around the house, we went for a remote control room stat. This uses an RF signal to transmit information between the thermostat and the boiler controls. Very posh.

The first job we tackled was draining the system down ready to do the bit of plumbing to install the zone valve. A zone valve simply controls where the water from the boiler goes. In our case the pump acts as a valve on the heating circuit so all we needed was a valve on the hot water side of things.

Whilst the system was draining down, we set to work installing the new programmer and the cylinder and room stats. I have to confess that the wiring was a little more of a challenge on this system than I imagined, but eventually we got it all working. And in truth, had I paid more attention to the wiring diagrams in the zone valve pack, I'd have got in working much sooner than I did.

So we now have the ability to set different programmes for the week and weekend, or we can switch to different programmes for each day. We have a very flash room stat that we can programme and move around the house to find the best position in which to use it.

The big plus is that the hot water no longer has to be heated to the same temperature as the boiler. I don't know how much that was costing us, but it will be interesting to see how much less gas we use this winter compared to previous years.

All in all a successful day and the stress has turned to delight as we tested the new controls and checked for leaks. Doing this sort of job just takes a little time and knowledge of how heating controls are meant to work. You also need to know how to empty and refill a system too and some basic plumbing skills. Actually the job is more about wiring than it is about plumbing. Permanent lives, switched lives, auxiliary switches etc, are all simple things if you know what you are doing. 

 Total cost was about £200 for all the controls, but that includes £40 for the remote room stat and £70 for the 28mm zone valve. I'm hoping that we'll knock that off the gas bill pretty quickly. I'm guessing, but I think on hot water cycles alone the boiler will now be off for 60-80% of the timed cycle. I think we'll get better heating output too when the hot water circuit shuts down and all the boiler output goes into the radiator circuit.

And to think , some people might have been tempted to suggest that I'd wasted my time at British Gas.