Smart heating systems to use with existing boiler and TRV wrestling

srichards

srichards

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I've been looking at these as I don't have a wall thermostat with my current heating system. There isn't anywhere sensible to put one and I sometimes want other rooms I'm not yet in to be warm when I go to them hence some sort of learning might be needed or at least remote control.

I've been looking at Tado which is quite smart and turns the heating on when you head toward home and it learns your behaviour patterns. It also has weather compensation. It relies on your smartphone to know where you are.

I also found some danfoss z wave radiator TRVs which sound rather clever. There is a horstman controller thingy that might do some of it but it lacks the intelligence of the Tado. Zwave is similar to X10 and seems to be the new standard for home automation.

British Gas do hive, it's cheap but I don't like British Gas. It's also just a smart phone controllable box with weather compensation to run the boiler basically so nothing really wow.

Another one is the honeywell evohome but that's expensive for zoning and you need to have their trvs on every radiator and each one would take batteries which would annoy immensely as it means having to change 20AAs a lot. Base price is about £315 for that with single zone for the entire house but I couldn't see any of the smarter functions and adaptive learning that the Tado offers.

I was thinking if the Tado could be integrated with a few intelligent trvs without them 'fighting' about whether the heating is on or not it would be perfect.

I found another called Heat Genie which has movement sensors as an option so it could heat rooms you were in only. Not sure whether it would be triggered by cats and I can imagine them standing shoulder on shoulder to make the radiators come on... Each radiator valve is £50 but the pir thingies are £100 a pop so can add up quite a bit.

The majority of them have a box for about £250 then optional radiator thermostats. My ecohome has programmable TRVs from about £25 each which is cheap. You need a link box to programme them via which remains plugged into your home network. That is about £40. Again cheap. I thought about using a few of these to control temp in various rooms but the problem is there would be no way of signalling back to the boiler when there was no demand so the pump would run all the time if I set the boiler to constant; so it would be less energy efficient than just having it on timed most of the time.

Anyone looked into these as well?
 
Depending how much you want to spend and how much you want to save.
Firstly don't listen to many figurers that are flying round...for example BG will come to sell you a boiler and talking about new boilers and how efficient they are and the 100"s of pounds you'll save....it's rubbish.
Condensing boiler are approx 97% efficient but older fan flued boilers can work at near enough 90%....they base their figurers on very old open flued boilers that were working at under 50% efficient.
If it was me I'd simply put in a programmable wireless room stat and set your thermostatic valves to the number that makes each room feel comfortable.
If you've got a very large property you can save money but getting a lot more involved but bear in mind that manufacturers are always making products that will make them money and very often will not be much of an advantage to the consumer.
IMO money would be better spent on ensuring your boiler is well serviced and working at its best and ensuring your system is clean. Many many systems have sludgey dirty water in them and whereas this won't effect the efficiency of the boiler it will effect how it works.
A little disclaimer....due to how TP seems to have become of late these are just my options based on being a heating engineer for over 30 years, others options are valid but if they differ to mine please don't spit your dummy in my direction :)
 
Martyn D said:
If it was me I'd simply put in a programmable wireless room stat and set your thermostatic valves to the number that makes each room feel comfortable.
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This is what we did, coupled with serious updates to insulating the house.

Martyn D said:
A little disclaimer....due to how TP seems to have become of late these are just my options based on being a heating engineer for over 30 years, others options are valid but if they differ to mine please don't spit your dummy in my direction :)
Click to expand...

Ah, not the voice of experience then! :D
 
I've done some insulation already and it has made a difference.

The boiler I have is an old Worcester 240 RSF. Non condensing. I think they are supposed to be 70-80% efficient but that isn't enough to cover the cost of a new boiler which will probably only last 10 years before dying.

The temperature that a room is comfortable varies according to time of day so the sitting room needs to have a higher setting in the evening than in the morning. This is why I was looking at programmable trvs as it means I wouldn't be over heating the sitting room when it isn't needed but at the same time not under heating other rooms.

Maybe just one programmable trv in the sitting room would do it. If I used a wall stat in there then it would mean the upstairs would also be too cold of an evening as the sitting room is quite cosy.

This honeywell one looks quite sensible and you don't need a separate thing to programme it with:
http://www.amazon.co.uk/Honeywell-E...ogrammable/dp/B0051UHFEI/ref=pd_sim_sbs_diy_6


I do like gadgets though :)
 
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IMO room stats are just an annoyance that building regs insist on.
Even if you had programmable thermostatic valves the stat would override them so it would just need to be put on max.
Just think of your health and getting exercise, when getting up put the valve on rooms not being used to, say, 2 then in the evening run upstairs at a vigorous pace and turn them up....you'll save money on unnecessary gadgets, have some exercise and also spare money for extra camera bits ;)
 
Martyn D said:
IMO room stats are just an annoyance that building regs insist on.
Even if you had programmable thermostatic valves the stat would override them so it would just need to be put on max.
Just think of your health and getting exercise, when getting up put the valve on rooms not being used to, say, 2 then in the evening run upstairs at a vigorous pace and turn them up....you'll save money on unnecessary gadgets, have some exercise and also spare money for extra camera bits ;)
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I already have to do that as the boiler programmer can only do 2 times a day and I need 3 really. I was thinking about making a robot lego arm that would press the boiler button while I was still on the sofa...

I think I'll cough the £40 odd for the honeywell one ;)
 
Interesting thread :)

A change of heating system is something I've been considering for a while as my current baxi non condensing boiler heats water in a tank rather than on demand and the radiators don't have thermo valves. Plus, the room stat is in the lounge that also has an exposed stair well so all my heat happily dances it's way upstairs :eek:
 
Normal TRVs are under a tenner a pop so you could do all of them in the house for a modest cost.

I did see some heat recirculating doodads on my travels so it is possible to capture the heat that wafts off upstairs and encourage it back down.. Friends had this in their old house as it had a mezzanine floor so all the heat shot straight up and disappeared so upstairs was always toasty but downstairs was artic if they didn't remember to switch it on.
 
With British gas's continuing mission to bankrupt me, I'm going to have to do something. Heating a water tank twice a day for a five minute shower a couple of times a day is a major part of my gas expenditure I think.

I know what you mean about downstairs being arctic, I can be sweating up stairs wearing shorts on minute and then when I go down to watch tv I'm snuggled under a blanket on the sofa!
 
I'd go onto the uswitch site and check your tariff and see how much you could save by switching away from BG. They can be very expensive if you don't hassle them regularly and make sure they're putting you on the best deal too.

There are boiler efficiency thingies floating about so I'd check the boiler model on that. If it is less than 70% efficient then switching to a condensing combi and getting TRVs might help over the long term. If it is already 70% or more then using it more wisely is probably the best way to save money.

There are add on flue heat recovery systems that help with efficiency.

Just found this for baxi:

http://www.energysavingtrust.org.uk/Take-action/Find-Energy-Saving-Trust-Recommended-products

Baxi Multi-fit GasSaver GS1 Passive Flue Gas Heat Recovery Device

Which is on the energysaving trust site which you can't link to directly, just the start page.

http://www.baxi.co.uk/gas-boilers/multifit-accessories.htm

Not sure whether they are any good for non combis though.
 
Cheers for the links, I'll have a look at them when I get home.

My boiler is original to the house, so around 1995 ish, can't imagine it's going to be all that efficient compared to modern models.
 
digitalfailure said:
My boiler is original to the house, so around 1995 ish, can't imagine it's going to be all that efficient compared to modern models.
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No, but...

We had a new boiler fitted when we moved in 1994. It's still going strong. Every year we have it serviced, and the engineer says we shouldn't even be thinking about replacing it. Yes, a modern one would be more efficient in a technical sense. But it would also be very expensive, AND it would very likely have a shorter life expectancy. In his opinion the whole-life costs for new combi boilers are considerably higher than for 'traditional' boilers like I have and like you probably have.
 
Martyn D said:
IMO room stats are just an annoyance that building regs insist on.
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I agree totally. I have no idea why they insist on a thermostat. Why control the whole house based on the temperature of one room?

A thermostatic valve on each radiator is a much better idea so why insist on having a room stat as well?


Steve.
 
Steve Smith said:
I agree totally. I have no idea why they insist on a thermostat. Why control the whole house based on the temperature of one room?

A thermostatic valve on each radiator is a much better idea so why insist on having a room stat as well?


Steve.
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TRVs won't stop the boiler when the required temperature is reached, which a room stat will....if you just use the TRVs then the boiler will be running the pump all the time while it is set to be on but with a thermostat in place it will go off altogether once the right temperature is reached. If it stays above the stat temperature then the boiler won't start up again. If you just have TRVs then the water carries on circulating so you're using extra electricity all the time.

Room stats in the right place and set the right way relative to how you want the rest of the house are ok but can be a pain if you have mismatched heating/cooling in various rooms.
 
I've had the honeywell evohome for nearly two years and had to change the batteries yet.

For individual control of rooms there is nothing better. Yes it is the most expensive but it is also the best.

They are releasing a new version in Feb that lets you control via your smartphone.

If you are near West London you are welcome to come round and have a look.
 
Steve Smith said:
No but the boiler's internal thermostat will.



Steve.
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Pump will keep running though. That's 100-200w of electricity being used 24/7. It's certainly the case with my boiler as I checked with worcester.
 
inkiboo said:
I've had the honeywell evohome for nearly two years and had to change the batteries yet.

For individual control of rooms there is nothing better. Yes it is the most expensive but it is also the best.

They are releasing a new version in Feb that lets you control via your smartphone.

If you are near West London you are welcome to come round and have a look.
Click to expand...

Thanks. I'm cheap though so just the Honeywell stats in a couple of key rooms is what I'm going to start with :)
 
srichards said:
Pump will keep running though. That's 100-200w of electricity being used 24/7. It's certainly the case with my boiler as I checked with worcester.
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It should only over run for a few minutes then stop. Most boilers are supplied with a wire link across the thermostat terminals so that you can run them without thermostats.

However, if you are talking about traditional vented systems with a separate pump, rather than a combination boiler, you could be right. Although it won't be 24 hours a day as you probably have a timer as well.


Steve.
 
Interesting. I have a few rads without trvs so that might explain it. I left it on low for several weeks 24/7 during the very cold winter. Don't think the pump ever stopped. Its a sealed combi system.

Might have to get a few normal trvs and a few of the fancy Honeywell ones :)
 
srichards said:
Its a sealed combi system.
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The boiler will fire up to maintain the temperature as set by its internal thermostat. When this temperature is reached, it will shut off the gas but will keep the pump running for a few minutes (probably about ten). This is called over run (at least, that's what Vaillant call it) and its purpose is to prevent the heat exchanger from overheating.

If you turn off all of your radiators as an experiment, you will probably find that the pump will switch off quite quickly.


Steve.
 
Steve Smith said:
If you turn off all of your radiators as an experiment, you will probably find that the pump will switch off quite quickly.
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Not all boilers are internally bypassed, so turning off all the radiators could make the pump try to pump water where it can't go (this is why it is usual to leave one radiator without a TRV, so water can always flow around the system).

Note : I am not a plumber, this is just what the people I had round to quote for a new boiler told me.
 
onomatopoeia said:
Not all boilers are internally bypassed, so turning off all the radiators could make the pump try to pump water where it can't go (this is why it is usual to leave one radiator without a TRV, so water can always flow around the system).

Note : I am not a plumber, this is just what the people I had round to quote for a new boiler told me.
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I've always been told the same...
 
Since I'm here, I'll describe my system. Combi boiler and Honeywell CM927 wireless programmable stat and TRVs on everything. I had an old dial type stat when I moved in, but replaced it myself last year.

I have the wireless part of the stat in the lounge, which is the room I want comfortable. It's also the room which needs the most heat, as it's the largest and three of the four walls are external. I have the TRVs on both rads at maximum. I then set the TRVs in the other rooms to make the comfortable when the lounge is at the temperature I have set. The boiler is always on, I don't use the timer on it, but I have programmed the required temperature on the Honeywell to vary at different times (19c in the evening and weekend daytimes, 15c overnight and weekday daytimes)

I looked at the tado system but the thermostat on that is wired so would have to go where the original dial stat was (in the hallway, where the "base station" part of the Honeywell is now wired in), unless I got involved in rewiring. The hallway is the one bit of the house I don't care about the temperature and doesn't actually need heating anyway, as it's surrounded by heated rooms, so I always found it a strange place to put the thermostat.
 
Steve Smith said:
I agree totally. I have no idea why they insist on a thermostat. Why control the whole house based on the temperature of one room?

A thermostatic valve on each radiator is a much better idea so why insist on having a room stat as well?


Steve.
Click to expand...

I guess it was some guy sat in an office trying to justify his job that implemented such a stupid reg.
I went on an energy efficiency course a few years back and a few of us asked why TRV's are said to be an efficient way of heating when they are overridden by a single room stat...they had no answer...says it all
 
onomatopoeia said:
Not all boilers are internally bypassed, so turning off all the radiators could make the pump try to pump water where it can't go (this is why it is usual to leave one radiator without a TRV, so water can always flow around the system).

Note : I am not a plumber, this is just what the people I had round to quote for a new boiler told me.
Click to expand...

Very few boilers (excluding combi's) have internal bypass's but if they are installed correctly then an auto bypass is put in the pipework between the pump and diverter/zone valves.
As Steve has mention, boilers have pump overruns and if the programmer has gone off the diverter/zone valves will be closed so even if one rad has no TRV it won't help as the pump will be pumping against a closed valve, hence the auto bypass being required.
 
Martyn D said:
As Steve has mention, boilers have pump overruns and if the programmer has gone off the diverter/zone valves will be closed so even if one rad has no TRV it won't help as the pump will be pumping against a closed valve, hence the auto bypass being required.
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It's not a major problem though as what we are referring to as pumps are actually circulators. i.e. they are not capable of pumping water up to any height but they can circulate water around a system when there is an equal, balanced amount either side. A pump running without the means to move the water around isn't really going to damage it or even strain it.

Martyn D said:
Very few boilers (excluding combi's) have internal bypass's but if they are installed correctly then an auto bypass is put in the pipework between the pump and diverter/zone valves.
Click to expand...

I have never fitted a bypass loop in the pipework but I have fitted TRVs on every rad but the bathroom to provide one. Bathrooms usually need a bit of extra help in the keeping warm department!

Martyn D said:
The hallway is the one bit of the house I don't care about the temperature and doesn't actually need heating anyway, as it's surrounded by heated rooms, so I always found it a strange place to put the thermostat.
Click to expand...

On the rare occasions that I have fitted a room stat, I have put it in the main bedroom. It's going to be much less prone to changes caused by people walking about and opening and closing doors than a downstairs room.


Steve.
 
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I was always under the impression that the room stat should be put in the coldest room or hallway if TRV's are to be fitted on the rads
 
Holy thread revival time...

Well I've ordered a Tado. They have a new model out and a low cost rental option offer tempted me into finally actually doing it. I have got a Salus programmable doofer as well if the Tado turns out to be a complete pain. That is a wireless programmable one that can do 5 temps a day.

The whole idea that the further away you are the more Tado will let the temperature reduce is quite clever.
 
I was always told you wouldn't put a room stat in a room which has a radiator with a trv.
 
I think current building regs require trvs on all rads and at least one room stat. As long as the room stat turn off the heating temp is lower than the highest one reachable with the radiator under normal conditions then it shouldn't matter that much theoretically should it?
 
The timing of this thread revival is poignant. I'm just about to push the button on the components needed to turn a Rasp Pi into a smart thermostat. Well, the components needed to at least prototype the idea.
 
Ooh. Good idea! I keep thinking about getting a Pi but never quite get around to it.
 
srichards said:
Holy thread revival time...

Well I've ordered a Tado. They have a new model out and a low cost rental option offer tempted me into finally actually doing it. I have got a Salus programmable doofer as well if the Tado turns out to be a complete pain. That is a wireless programmable one that can do 5 temps a day.

The whole idea that the further away you are the more Tado will let the temperature reduce is quite clever.
Click to expand...
I've been looking in to getting a system like this. I was considering the Hive from BG but this Tado system looks a lot better for around the same cost.

Are you going for the self installation option? If so could you let me know how you get on with installing it please?
 
I'm going to get my normal gas bloke to install it. I don't think it is that hard if you already have a wired thermostat. It's best attempted during normal office hours though as that is when the Tado support team are available.
 
I have evohome, and 12 zones/16 rads, 2 towel rads. It's brilliant. It has more than paid for itself in just over a year, including the valves. It's great because of the individual zone control - all my rooms are temperature controlled individually, unlike a single smart thermostat that is turning the whole house on or off, which seems as nuts as controlling all your lights with a single light switch. I leave infrequently use rooms at set back temperature all the time, and other more frequently used rooms get to temperature really well, because the boiler is working so much less. I have the Gateway to the internet, and it's fantastic for tweaking settings if you are going to be home early, or if you've forgotten to turn it down for holidays etc. It also now integrates with IFTTT, so you can set up geofences with smart phones to turn off when you leave the area, or turn on when you get within a certain distance, or even to turn a room on to coincide with a diary event in gmail. As for batteries - I think i've changed 4 AA's in just over a year and my year on year heating costs, even in spite of the energy increases we've had, are 33% less than they were.
 
All rooms have rads with TRVs, or will do, so technically they are all controlled individually ;)

I think their new smart thermostat does offer zone control as you fit one per zone.

I'm sure Tado will come out with lightwave or similar TRVs at some point.
 
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