3 weeks with a dual zone heating system, and now...

[TheOldFellow]

Three weeks after I fitted a new heating zone for a bedroom/ensuite we are really finding it a boon. Before, when the sitting room was warm enough, the rest of the house got no heat, despite the TRVs, since zone valve and boiler were not being called. Now, at least we've got a warm bedroom. (The house is a long thin bungalow, so heat in one room never affects another, unlike a conventional house).

It's so good, I'm going to divide off another zone for separate control.

I can't thank you guys enough for your help in planning this, and for the encouragement. Especially ARW for his help getting the wiring right - easy when you understand.

R.

[ARWadsworth]

I am glad it works. So what is the other zone do you want?

You have seen the nice new diagrams that Dave Osbourne did for the for the wiki?

[<me9]

It doesn't include the version I want (modified S plan but with the hot water having priority. Also possibly a different signal to the boiler for hot water to be at a higher temperature to the heating.

I'm thinking aloud here for when I replace my system boiler with a more modern one, probably WB. I currently have two heating zones and hot water, which was effectively prioritised until I replaced the 3 port valve (used as a diverter) to teh cylinder with a 2 port one.

[Steve Walker]

Nah, go the whole hog and have every room as an individual zone, each with it's own timerstat! That's what I've got at the moment, but I keep meaning to get round to making my own controller, allowing for sensors and valves for each room, plus outside; a central controller; and a couple of dedicated control panels with lcd display, etc. With a wife, three kids and a load of diy to do, I just haven't got the time to design and program it at the moment though :(

[dennis]

I expect most systems using two port valves prioritise the hw anyway. They tend not to have any way to balance the hw circuit and its usually a very low resistance compared to the ch circuit.

[TheOldFellow]

Yes, I would like to do that, but like you, I have so much on with another bathroom to renovate (I'm planning to move walls, doorways etc. to expand the study and shrink the bathroom). But there is space for another zone, and an easy way to wire it up. If I do that I get:

Zone 1: Living Room and Kitchen. Zone 2: Study, Master Bedroom and Bathroom. Zone 3: Guest Bedroom and Ensuite.

I planned for this and left a stub of 22mm in the 'manifold' of the pumped feed, and another in the common return flow. I'm also introducing full-bore service valves in lots of places to cut out drain-downs.

Someone will be along to say that the boiler won't modulate properly with this set up, but mine is oil and non-modulating. What I probably should do is have a thermal store in the loop, but that's for another year...

R.

[TheOldFellow]

Yes the diagrams are smashing. Unfortunately my wiring centre is the PCB kind - for plumbers who can't read diagrams :) The principles still apply though.

The other zone is to give separate control to the non UFH part of the house. The zone I just did was a Guest Suite. The UFH is just too good, so I need different control for the non-UFH part.

I'm also considering ducting warm air from the ceiling of the UFH zone to another part, as it also has the most solar gain, and often gets too hot.

R.

[Roger Mills]

Depends how it's timed. If you have independent timers on HW and CH, you can contrive that they're not generally on at the same time.

[ARWadsworth]

I suspect that the same is true for Y plans. I swapped my brothers programmer as he complained that the CH was taking too long to heat up and that it only ever got completely hot when the HW was satisfied/off. This also saves him money as he has limited the times of the HW to when he needs it to be hot.

Adam