wireless thermostats and beyond

[stuart noble]

The situation is that a friend wants to remotely turn a boiler on and off that's 3 floors down in the basement. Possibly an ordinary wireless stat would work but, if it doesn't because of obstructions etc, there seem to be ways of sending your boiler an SMS message or totally controlling it from your IPhone. Sounds crazy but, alone in a flat with a baby, it's not that easy to nip up and down the stairs. Anyone got any experience with this sort of stuff?

[The Natural Philosopher]

Mmm.

wireless stat may as you say be pushing it.

easiest is to use existing wiring maybe and a homeplug thingy..

If try an run a cable probly. More reliable.

[stuart noble]

Alas no possibility of running any cable, and it's a big building with lord knows how many circuits, so I'd have my doubts about homeplugs.

[YAPH]

Why do they want to turn the boiler on and off? A heating control system that can do that for them whilst maintaining the desired temperature at set times? A Honeywell CM927 (or 921 for a 1-day version) wireless programmable thermostat might fit the bill. The progstat controller bit then goes in the flat and the relay unit in the basement beside the boiler.

[Roger Mills]

The question seems to be whether the wireless signal would work reliably through 3 floors of (probably concrete) structure. Do you have experience which suggests that it would?

[stuart noble]

Actually this is a Victorian conversion with wooden floors, but there may be other other obstructions I'm not aware of. Having one boiler for 8 privately owned flats is slightly crazy in this day and age, and will no doubt be changed if the majority can agree, but an interim solution for next winter is what is needed.

[Dave Liquorice]

Er they don't really want to turn the boiler on/off surely? What about the other seven tenants?

The obvious solution is a zone valve on the heating feed from the boiler in the flat controlled by the flats thermostat. It's not quite that simple as the bolier should be turned fully off when there is no call for heat from any of the flats to prevent it cycling on the bypass (required if all the flats can shutdown).

This shared boiler must be a billing nightmare as well.

[stuart noble]

The other tenants are single, and out all day, so may not take kindly to the whole place being heated during the day. Some kind of excess fuel supplement on the service charge is envisaged, but I dread to think what that might amount to. The couple in question are hoping to sell up and move during the summer but obviously they can't depend on that going to plan

That sounds like a good solution if there are separate feeds for each flat. However, this was a very early conversion and I wouldn't be confident on that score. I'll certainly tell them to get that checked out.

Strangely enough, no. Gas is included in the annual service charge, and has been only modestly increased in recent years because apparently the building is on some kind of industrial rate. I don't know the details, but it must have been beneficial for the management to have stuck with it for this long.

[Dave Liquorice]

There might not be a pair of pipes from the boiler to each flat but there may be a common riser that has a single feed T'd from it for each flat.

The costs of installing individual boilers and associated gas pipes and meters, possibly needing an uprated supply etc I would expect to be quite high. If the gas is a bit cheaper and most tennants have similar use profiles then it probably does make sense to stick with this "odd" system.

If there is some form of flow/return pipe work for each flat one could install a couple of temp sensors and a flow meter and measure the amount of energy each flat consumes and then divvy the bill accordingly.

[The Natural Philosopher]

The actual final obvious solutions is a timer, thermostat and indeed zone valve for each flat wired 'OR' to the boiler.

[stuart noble]

Ah, that's interesting. So presumably, whatever pipework there is, the feed would be easily accessible from inside each flat, so it should be a relatively non-invasive process to install individual controls. That arrangement would appear to benefit all the flats, and would probably pay for itself quite quickly. Many thanks for the suggestions.

[Dave Liquorice]

checked

But be aware that the block of flats might have 3 phase supply. The block of 14 individual flats I used to live in has a 3 phase incomer that was then split to indivifual single phase meters for each flat and another single phse meter for communal areas.

So "live" in one flat might a different "live" in another... Ideally the mains for the time switch, stat, valve etc in each flat is fed from the main heating system isolator so some one working on it doesn't get a surprise from one of the "or" lines coming from a flat. Then fit an isolator where that boiler mains feed enters each flat so those parts can be worked on without having to switch off the entire system. Oh don't forget that you need to switch the "or" wire as well so that doesn't come live from another flat...