Z-Wave..................or not?

[RedSlayerA]

Hi everyone. I'm not a plumber (but God knows I wished I took a plumbing apprenticeship rather than aerospace engineering).
Sorry about this novel - I hope that someone can be bothered to read it.

My latest gas bill was £400 for 2 months (don't laugh - we had it on 24/7 to keep cats warm ffs, due to one of 3 cats that is insistent on spraying every surface in the house). And no, we can't kill the cat - without me getting it too.
The house is a medium semi-bungalow, with dormer. It ain't a mansion.

I have installed a full combi central heating system in a very small bungalow (which I believe is a lot harder than in a large house personally - it's hard work routing pipework neatly, in a concrete floored box), which taught me one, very important lesson: I do overtime in the job I'm skilled at, and I pay a plumber to do the job that they are good at.
It was probably a good learning experience, but the gloss wears off after 2 months of knee-cap crumbling pipe-fitting. ;-)

Before I call in a plumber however, I need to know that what I want is possible (otherwise - my current system is what it is).

I'm logically certain that there must be a way of having any (and every) individual thermostatically controlled radiator - control the boiler.
E.g. Each and every radiator should be able to thermostatically switch on / off, which then sends a signal to the boiler.
If the boiler is on already - all is good, if not, it must react and switch itself on.
When the last radiator has switched itself off, then the boiler must 'know' this and stop.
I envisage a wireless system, and the house enables good wifi signal throughout (I've experimented with wifi forwarders etc. also, which work well).

I want to get rid of the current, central 'house' thermostat in the hall.(Waste of time and space).
I have 10 radiators, with plans for another in the conservatory (which I expect to be the one to be switching on/off most regularly) - where the cats will reside when we're not in, or at night time.
P.S. the cats can get in / out of the conservatory due to a cat-flap that recognises individual electronic cat-tags.

I'm not sure how my house is piped, but I am hoping it is one main 'ring', with all radiators spurring off that. (I need to test that and the only way I can think of doing that, without pulling up all hard-wood floors is switch em all off - opening one thermostat at a time).
The current combi-boiler seems to be 16 years old, no problems experienced so far.
Vaillant Turbomax Plus 824E with 'boiler interlock' provided (according to the commissioning / service record). I assume that 'boiler interlock' means that it can be switched automatically - by the hall thermostat?
It has an analog, 24 hour, circular dial-type timer setting.
Here are the radiators:

Front room = 2
Hallway = 1
Bed Down 1 = 1
Bed Down 2 = 1
Bathroom Down = 1
Kitchen = 1
Bed Up 1 = 1
Bed Up 2 = 1
Bathroom Up = 1
Conservatory = (to be installed)

So, so far, I've come across the following, and before getting too enthused about 'Z-Wave' - I would appreciate some expert / experienced opinions - if you would be so kind (and if you're in the Lancs / Fylde area - I'd be happy to meet you / receive a quote (some new radiators are also required, and, this new setup may require a different boiler being fitted - I don't know)).

Here's the link to the products I've been looking at: Boiler-Radiator_Multizone | Vesternet

I want to control all radiator settings wirelessly.
Up to now, I THINK I'll need:
For 2 radiator living room: 2 x Fibaro Radiator Heat Controller Z-Wave Fibaro Heat Controller
For all other radiators: 8 / 9 x Z-Wave StellaZ Radiator Thermostat Z-Wave StellaZ Radiator Thermostat
For central 'control': 1 x Hub/Controller Controllers | SmartThings | Platforms | Smart Home | Vesternet
(I have Amazon hub and echo dots if that is relevant).

Questions:
1) Can this analog timer wiring be intercepted with a digitally controlled 'hub controller'?
2) Do I need this specific 'hub', or does the Amazon 'ALEXA' hub have some capability?

My main criteria is: I want the boiler to switch on dependent on ANY radiator requiring it, and off when ALL radiators don't require it, with a pretty close second priority of: all radiator temperatures MUST be wifi controlled (even away from home).

Any ideas / suggestions welcome.

Red ;-)

 

[Chuck]

which taught me one, very important lesson: I do overtime in the job I'm skilled at, and I pay a plumber to do the job that they are good at.

And the rest of your post illustrates how very true this is.

The boiler you have chosen has a minimum output of 8.9kW, which makes the over-complicated controls with independent demand signals pointless because the system will be short-cycling for much of the time and the result will be uncomfortable. In any case, it's a bad idea to try to have different parts of a house at very different temperatures because you'll get condensation problems.

I suggest you employ a heating engineer who can do the heat loss calculations for your bungalow and then get the radiators correctly sized and balanced. If this is done properly you won't need complicated controls.

Heating a whole conservatory at night for a couple of cats seems a strange (and very costly) choice to me. Unless you've got money to burn, I'd look at other options for them. E.g. a nicely insulated basket and a warm pad or perhaps a small area of electric UFH to give them a warm patch at night.

 

[gmartine]

Chuck beat me to it.

What you want is all the rooms to get up to the desired temp at roughly the same time and then the thermostat which is controlled by an index radiator to switch the boiler off, that is boiler interlock. That requires the system to be balanced irrespective of how you control the TRV's, wirelessly or otherwise. What you don't want is one radiator calling for heat when the others are shut down, that'll just cycle the boiler like crazy and is extraordinarily inefficient.

 

[Murdoch]

Some of these may help:

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