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General => Temperature Monitoring & HVAC Control => Topic started by: mzpost on November 30, 2015, 09:50:12 am

Title: Zwave TRV's - worth it or not ?
Post by: mzpost on November 30, 2015, 09:50:12 am
So for a while I've been thinking about zwave TRV's (thermostat radiator valves).  I've read some good, bad and terrible reports about them and I see another model is now available from another Mfr. 

I wanted to see how people were finding them in the real world .

Firstly my heating is still going to be controlled by a main thermostat (just about to give that job to a nest 3), this will run on a schedule and will take care of itself as at this stage I have no desire or real need to have Vera control my heating schedules (as my heating works fine on a program and thermostat and has done for the last 15 years). 

The reason I'm interested in Zwave TRV is to give a little more control to room temps in the evening.  I like to go to bed in a warm room and wake up in a warm room but dont want to warm all night as prefer a cooler room.  I'm thinking it should be simple to have the TRV drop the temp in the room in the evening and then turn it back up around wake up time (whilst allowing the rest of the house to get up to temperature so its warm when I get up.

On paper it should be simple and easy to achieve with a simple scene, I was keen to see how people are getting on in the real world.
Title: Re: Zwave TRV's - worth it or not ?
Post by: Slartibartfast on November 30, 2015, 09:52:43 am
If you only want to add local control to rooms, why not integrate into the heating system direct. Rather than nest, consider evohome which gives full temperature and schedule control to every room.
Title: Re: Zwave TRV's - worth it or not ?
Post by: mzpost on November 30, 2015, 10:14:55 am
Really interesting point as I'd looked at that.  Half of me says heating should just do its own thing as a stand alone system, half of me says if I'm doing this I should have one eye on the future and being able to integrate with other things (i.e. turning on the heating in that room if someone walks in which would be easy to do via zwave.

I was thinking that Next and some Zwave TRV's gives me a best of both worlds scenario (of course it could also give me a dogs breakfast half way house).

As evohome is Wifi in theory it should be able to talk to other things, that will depend on honeywell wanting to open it up.  With nest (I almost went hive until nest 3 popped up) at least I know it already talks to other stuff including my nest protect etc.

Are you using the Evohome system, it has some great reviews.
Title: Re: Zwave TRV's - worth it or not ?
Post by: Slartibartfast on November 30, 2015, 10:52:20 am
I have Evohome which I installed thus summer. Only just started to come into its own.

I like that rooms which are normally unused are kept at a low temperature and rooms in use are heated at the times they are used. My office heats up on weekdays during working hours and is kept cooler at weekends and evenings.  Every room has its own schedule for temp and times. I have thirteen TRV's. The hot water is on its own previously existing timer as I didn't need more control than that. It even looks cool on the wall.

I did not see any reason to tie in to vera as heating does not go up and down quickly enough to turn on as someone enters a room. I also wanted a system which was stand alone in case of vera problems.
Title: Re: Zwave TRV's - worth it or not ?
Post by: mzpost on November 30, 2015, 10:59:12 am
Thanks sounds ideal.
Title: Re: Zwave TRV's - worth it or not ?
Post by: mzpost on December 04, 2015, 01:05:52 am
Quick question if I may, have I read correctly that if a trv needs to heat a room it will fire up the boiler ?. If so that's a great feature especially if you want to do some clothes drying just on one rad.

Sounds like I'm going this route rather than a nest and some trv and pleg as the system firing up the boiler itself just for single rooms is really powerful and I believe heating should stand by itself.
Title: Re: Zwave TRV's - worth it or not ?
Post by: Slartibartfast on December 04, 2015, 03:02:56 am
For install, you can set the heating timer on constant and put the boiler controller contacts in place of your original thermostat timer controller. Now whenever any one zone needs heat, it fires up the boiler and opens the TRV on that room.
So simple answer is yes but because the boiler is only heating one room the room will reach temperature quickly and shut off again. No necessarily ideal for clothes drying. I suppose you just set on max and open a window to keep it on.
Title: Re: Zwave TRV's - worth it or not ?
Post by: mzpost on December 04, 2015, 03:26:19 am
Excellent thanks I think I'm going this route.  Really does seem the best option for good control. 
Title: Re: Zwave TRV's - worth it or not ?
Post by: Slartibartfast on December 04, 2015, 03:57:18 am
As an example. This morning, the one bedroom was heated just before we woke. Also the kitchen diner, bathroom and landing. By the time we were breakfasted, showered and dressed, the heating in the bedroom and bathroom was set down and my office was warming up. The other rooms are just heated to a point where they are okay to visit but now to stay in.
Knowing your normal routine allows you to have rooms warming up and cooling down as required during the day.
 
For one off changes, my wife is happy to know she can just turn the dial on the TRV and not mess with the controller (its dead easy but she is a real luddite) and I am happy to know that at the next time point it will correct back to normal. No more following here round turning things down all the time.
 
If you have basic electrical knowledge you can fit it for yourself.