Boiler timer compatibility

[telnet]

Hi, We want a Vaillant combi because it is by far the quietest and will be located near the bedroom. My gas installer usually does Baxi and told me to make my own choice from the Vaillant range

I have selected an ecotec plus 832

https://www.vaillant.co.uk/for-inst...V6b3tCh1kbAV9EAAYAyAAEgI0XPD_BwE&gclsrc=aw.ds

Now, Vaillant sell this timer/thermostat

https://www.vaillant.co.uk/download...llation-instructions-0020131978-00-418486.pdf

My question relates to the wiring diagram to connect the RF receiver/relay to the boiler on p14.

We don't want to use the Vaillant thermostat because it does not seem to have a simple button to turn the heat on and off manually. I was therefore considering this unit.

https://www.wolseley.co.uk/wcsstore...lang.all/ti/on/Center_340010_Installation.pdf

My question is whether it is compatible with the Vaillant system? Also, am I right in thinking that T1 and T2 in the Center wiring diagram is equivalent to the terminal marked Bus +/- on page 14 of the Vaillant installation guide?

I presume my gas fitter would know but I don't want to be running round town looking for the correct timer half way through the job.

Thanks for your advice.

 

[flameport]

Also, am I right in thinking that T1 and T2 in the Center wiring diagram is equivalent to the terminal marked Bus +/-

No, they are entirely different. Connecting one to the other is likely to result in something being destroyed.

+/- are the eBus connection, for use with thermostats that communicate various information between themselves and the boiler.
The Wolseley thermostat is a basic on/off device.
Either type can be used with that boiler, but they most certainly do NOT wire into the same terminals.

My gas installer usually does Baxi and told me to make my own choice from the Vaillant range

That is most likely because they are shifting any liability for problems onto you. Suggest you get someone else who can both supply and install.

 

[telnet]

No, they are entirely different. Connecting one to the other is likely to result in something being destroyed.

+/- are the eBus connection, for use with thermostats that communicate various information between themselves and the boiler.

Thanks for the info.

The Wolseley thermostat is a basic on/off device.
Either type can be used with that boiler, but they most certainly do NOT wire into the same terminals.

Great, the installer will sort out the terminals. Meanwhile, can you tell me what is the advantage of this extra information on the eBus that the Vaillant thermostat is exchanging with the boiler?

The reason I was looking at the simple on/off device is that all the rad valves are up full and my wife turns the heating on till it is too hot and then she turns it off. I've tried to explain the merits of a constant temperature but to no avail. She also turns lights on and off as she walks from room to room. What can you do?

That brings me to my next question: If the Wolseley thermostat is a basic on/off device, I presume it will just turn the heating on and off without cutting off the hot water? I am 99% sure but just asking to be on the safe side.

That is most likely because they are shifting any liability for problems onto you. Suggest you get someone else who can both supply and install.

This is not the case. He is my next door neighbour. He quotes for Baxi because it is mid price mid quality and his quotes have to be competitive if he wants to work. We will pay for a Vaillant because it is >10 db quieter than the Bosch or the Baxi. However, I take your point. I will just tell him my selection and he can go and buy it from the merchant.

Thanks for your advice, which is very useful.

 

[telnet]

BTW, I just saw the reviews for the Vaillant RTF350f on Amazon. I am definitely not going to fit one, I need something else.

https://www.amazon.co.uk/Vaillant-V...d=1557391634&s=gateway&sr=8-1#customerReviews

This has great reviews and a simple manual mode.

https://www.amazon.co.uk/dp/B072KL746L/ref=psdc_1938192031_t1_B00SI1D6FY#

I think I have all the info I need but comments still welcome as I will think it over the weekend.

 

[muggles]

Great, the installer will sort out the terminals. Meanwhile, can you tell me what is the advantage of this extra information on the eBus that the Vaillant thermostat is exchanging with the boiler?

It should make the boiler more efficient, and may also help to prolong its life by reducing the number of times it fires up & goes off. The bus controller will set the boiler's output to match what is required in the room, rather than the boiler guessing what output is needed based on the temperature of the water coming back to it.

The reason I was looking at the simple on/off device is that all the rad valves are up full and my wife turns the heating on till it is too hot and then she turns it off

Try harder to retrain her, or make her pay the gas bills for a bit until she understands that it's cheaper to keep the house at a comfortable temperature! Simple on/off controls are not compliant with modern building regulations, known as Boiler Plus, and so may not be fitted as part of a new combi boiler installation. Only Boiler Plus compliant controls may be fitted, which must utilise either weather compensation or load compensation as a means of control. Neither the Center nor the Salus controls you posted comply (Center say on their website that it complies, but the small print clarifies that it actually doesn't!)

 

[ianmcd]

if you dont want the Valliant I strongly recommend something other than the Salus they are not very reliable

 

[telnet]

Simple on/off controls are not compliant with modern building regulations, known as Boiler Plus, and so may not be fitted as part of a new combi boiler installation. Only Boiler Plus compliant controls may be fitted, which must utilise either weather compensation or load compensation as a means of control.

Does that mean you can't have a boiler installed with a simple pin wheel timer? As far as I can see boilers are supplied without control gear, giving the customer the option. Does this mean that this Vaillant timer is not compliant?

https://www.vaillant.co.uk/homeowners/products/vaillant-timeswitch-150-control-3713.html

 

[ianmcd]

yes you can have any timer and any thermostat that you like with your boiler, what @muggles is saying that if you were installing a new boiler now , then it must conform to a recent amendment called boiler plus, it is intended to reduce emissions and be more green,you dont have to retrospectively change your existing controls,as said mechanical timers and the like are simply on/off switches where as opentherm, will constantly "talk" to the boiler and tell it to modulate up or down as required and theoretically save you gas, you are however correct in that some of them are far too over complicated and they needn't be, it is just manus trying to outdo each other by adding different functions to sell their product

 

[muggles]

Does that mean you can't have a boiler installed with a simple pin wheel timer? As far as I can see boilers are supplied without control gear, giving the customer the option. Does this mean that this Vaillant timer is not compliant?

https://www.vaillant.co.uk/homeowners/products/vaillant-timeswitch-150-control-3713.html

That timer is compliant in combination with the VRT50 thermostat, but not on its own

 

[ericmark]

Theory is if the boiler turns down before it turns off, then when it turns off less heat is lost through the flue, for number of times the timer turns it off/on not worth worrying about, but for the thermostat it is, most expensive off/on wireless thermostats start cycling boiler off/on before set temperature to stop over shooting, so can turn the boiler off 100's of times a day, a modulating thermostat connected to ebus turns boiler down/up rather than on/off so gives better control and uses less power.

However trying to use the ebus is some thing else, when I looked into it Bosch used there own system which will only control one room. Other makes use OpenTherm which means third party thermostats can be used, but which and how and what it costs is not so easy to work out, theory is easy the TRV heads tell the hub/thermostat if it needs heat or not by reporting target and actual temperature and the hub then tells boiler what to do, however that means an expensive electronic head on every TRV with wifi, and in some cases it simply uses a follow command and you don't get the option to select different temperature and times for each room.

So most boilers can also modulate by measuring return water temperature, so instead of expensive wifi heads, you can use non wifi like the terrier i30 still set program for each room, but does not report to central hub, it controls boiler by return water temperature. However clearly if the boiler is not running it can't switch on the radiator, and using return water most boilers have anti cycle software so if all radiators are off it extends the time before it tries again to see if radiators want hot water.

So you often need to cheat, at least I did, by having the programmer turn off boiler at 3 am and back on at 6:10 am and having TRV heads select morning temperature at 6 am this ensured boiler runs when TRV heads temperature changes, and still need a wall off/on thermostat in the coolest room with no outside door and no alternative heating to turn off boiler on warm days.

With a Bosch boiler and 4 wifi TRV heads plus 4 standard heads the boiler worked reasonably well, as one or other TRV was open most of the time so boiler runs modulated down most of the day in winter, but it did take some setting up to start with. A heating engineer can set the radiators to approx the right setting measuring input and output temperatures, but only approx, using some thing like Tado or EvoHome he does not need to worry as the software will correct slight errors.

Setting up DIY can take time, and it took me two years with a little tweak here and anther tweak there to get it nearly A1. Had the boiler been OpenTherm enabled it would have been easy, but Bosch is not OpenTherm, I am sure they are good boilers, but it needs a lot of setting up because no OpenTherm.

Now other house is open plan and central heating control was thermostat down stairs on the wall and standard TRV's upstairs very easy to set up, main problem with this house was the bay windows catching the sun and room temperature soaring as a result, so much depends on the home.

Having got it all sorted now moving to a house heated by oil, so starting all over again.

 

[telnet]

OK, so that means I'm voting for Brexit if there is another referendum.

I mean what cant you do? The Vaillant wireless offering has ten 1 star reviews on Amazon:

"I have been a Heating Engineer for 15 years and have installed no end of Vaillant boilers, but regrettably their controls are hopeless. I currently have 10 or so of these controllers which randomly loose RF contact and revert to 2010 for no apparent reason. Please do not buy you will live to regret it."

Unfortunately, using an opentherm adaptor on a vaillant may void the warranty:

****************
OpenTherm Compatible Boilers – Unofficially Compatible
The following boiler models, mostly Vaillant and Worcester Bosch are capable unofficially. Using the mentioned adaptors may invalidate your warranty. However boilers that are out of warranty will have no known problems, as these adaptors are purpose made by the companies themselves for some European countries, where governments have made it compulsory to have OpenTherm.
**********************

Maybe my wife has the best strategy after all: turn the rads up full, turn the heating on till the house is hot and then turn it off till the house is cold. In fact, that's not exactly true as we tend to turn the rads in bedrooms off for 10 months of the year. So, these complex systems that keep your entire house at a constant temperature are not for us.

Indeed, we don't heat the house when we are out or in bed so we probably have a much smaller carbon footprint than the people these regulations are aimed at. So, it seems that we have to suffer the inconvenience of these regulations because of the snowflakes who overheat their houses. I know that does not make sense!

 

[telnet]

However clearly if the boiler is not running it can't switch on the radiator, and using return water most boilers have anti cycle software so if all radiators are off it extends the time before it tries again to see if radiators want hot water.

So you often need to cheat, at least I did, .

I may not be remembering correctly, but I think that the towel rail in the bathroom of my parents' old house was permanently on and that this was some kind of a failsafe for the operation of the boiler. That made me think that a workaround for the problem you describe is to take the valve off of one of the radiators, quite possibly the towel rail.

 

[ianmcd]

I may not be remembering correctly, but I think that the towel rail in the bathroom of my parents' old house was permanently on and that this was some kind of a failsafe for the operation of the boiler. That made me think that a workaround for the problem you describe is to take the valve off of one of the radiators, quite possibly the towel rail.

Yep very common to leave a bathroom rad or towel rad always open as a by pass for the boiler

 

[muggles]

OK, so that means I'm voting for Brexit if there is another referendum.

I mean what cant you do? The Vaillant wireless offering has ten 1 star reviews on Amazon:

"I have been a Heating Engineer for 15 years and have installed no end of Vaillant boilers, but regrettably their controls are hopeless. I currently have 10 or so of these controllers which randomly loose RF contact and revert to 2010 for no apparent reason. Please do not buy you will live to regret it."

Unfortunately, using an opentherm adaptor on a vaillant may void the warranty:

****************
OpenTherm Compatible Boilers – Unofficially Compatible
The following boiler models, mostly Vaillant and Worcester Bosch are capable unofficially. Using the mentioned adaptors may invalidate your warranty. However boilers that are out of warranty will have no known problems, as these adaptors are purpose made by the companies themselves for some European countries, where governments have made it compulsory to have OpenTherm.
**********************

Maybe my wife has the best strategy after all: turn the rads up full, turn the heating on till the house is hot and then turn it off till the house is cold. In fact, that's not exactly true as we tend to turn the rads in bedrooms off for 10 months of the year. So, these complex systems that keep your entire house at a constant temperature are not for us.

Indeed, we don't heat the house when we are out or in bed so we probably have a much smaller carbon footprint than the people these regulations are aimed at. So, it seems that we have to suffer the inconvenience of these regulations because of the snowflakes who overheat their houses. I know that does not make sense!

Don't know what Brexit has to do with it - Boiler Plus is English legislation (although like a lot of the energy efficiency legislation we pioneer, I expect it'll spread to Europe eventually). I don't heat my house when I'm in bed either, but I still keep it at a nice sensible constant temperature when I'm up and about. It saves money, simple as that, and you don't have to have a complex system - the timer you linked to with a VRT50 thermostat is actually very simple. I really don't understand your objection to it - it's easy to use, and will reduce your fuel bills. What's not to like? I'm not aware of OpenTherm being mandatory in other countries, but it is a preferred control protocol due to the aforementioned energy efficiency improvements and the ease of installation.

If how much noise the boiler makes is of primary importance to you, and you want a greater choice of control options, then the Ideal Logic C35 is 2db quieter than the Vaillant and accepts OpenTherm controls, so you're not tied to one manufacturer's products

 

[ericmark]

Fitted central heating myself in my house some 30 years ago and still running A1. But mothers house has always been a problem, not the central heating fault, it is the bay windows and the way sun warms the rooms.

Although not the fault of the central heating, good control can get around the problem, and that control starts with the TRV.

Basic idea, if the TRV turns off or down the radiator when room is warm enough, then as long as there is a by-pass valve then with any modern modulating boiler the boiler output will reduced or switch off to suit the demand. No need for any wall thermostat.

However the boiler would then every so often fire up and test to see if any heat is required, so adding a wall thermostat can stop the boiler cycling to test if required.

However fully automatic is very hard to get, I have it in my car so clearly not impossible, but for my car to control the climate it has to both heat and cool, I know with the Myson fan assisted radiators they have have twin matrix one connected to heating liquid the other cool liquid so the same radiator can heat or cool, but the cost is some what inhibitive so we tend to heat only.

So Winter heating house to 20°C in the morning great, but as Summer arrives, then we want house at 17°C in the morning so as the day goes on the house will not be at 28°C. I know with IFTTT we can use the internet to adjust heating according to weather reports, but most people work the controls manually.

So the central heating control is normally not perfect, and it required some manual intervention, the question is how much is reasonable?

One can wire as many on/off thermostats that you want in parallel, so the TRV stops the room getting too hot, and the wall thermostat ensure the boiler is running when required. If both are programmable you can have a near perfect system where the TRV and programmable thermostat in the same room are both set to same temperatures and times. So around £50 per room with no wifi or internet involved, only down side is wiring all the wall thermostats. Plus to be able to set it up, the TRV must be calibrated in °C.

Most house have around 4 rooms which are critical, so in real terms 4 wall thermostats, other rooms just a TRV and if slightly cooler than wanted not really a problem. And using that method no need for OpenTherm or any other modulating wall thermostat. Not perfect but good enough, and unless using Myson fan assisted radiators with heating and cooling all controls are not perfect, but could be good enough.