Neomitis RT7RF Plus

[whatsthenews]

I posted recently regarding our non functioning Salus wireless thermostat.

The bloke replaced it with a Neomitis RT7RF Plus.
Not been that happy with it as the optimisation mode doesn't seem to work and there's only the option to pre set 2 temperatures, ie one for "eco" and one for "comfort" . He also fitted one for my elderly mother and like us , with her last stat we could set different temps for different time periods. We can easily override the auto settings and remember to turn it back down.

I also noticed that we either have cold or hot radiators and nothing in-between .
Reading the old ( crap) Salus instructions and data sheet as well as the one for the new Neomitis I've discovered that the Salus had opentherm technology which was compatible with our Baxi modulating boiler.
The new Neomitis is just an "on" " off" control which surely defeats the object of having a modulating boiler?
I'm reading that by modulating the boiler is more efficient and by reducing the flow rate it also reduces wear and tear on the boiler.

Somewhat p..d off that he fitted this , especially when the stat " optimisation" mode doesn't seem to work..I set it ( in opti comfort mode) to be 20c at 0900 today and the boiler didn't fire up till 0900 so it was still only 18c when we got up.

 

[whatsthenews]

And the other thing I'm curious about is something that the Salus called " span" which could be set to either 0.5 or 0.25 ( °c)
No such info about the Neomitis but reading around maybe it's 1c ?
No wonder we're feeling chilly

The best temp control and " comfort" we had was when the Salus wasn't working and we had the receiver on manual and the flow temp on the boiler at around 55c first thing in the morning for 2 hrs, 40c for the rest of the day till about 22 30 and about 20c overnight.
Maintained the temp in the house at between 19.5 and 20c and temp at midnight was 19c and 17.5-18c at 0800 when we'd get up to turn the flow rate up to 55c.

We have big radiators and they're all convectors with TRVs

Maybe we'll just use the ' stat to get the heating to come on first thing in the morning

 

[JonathanM]

Is the overall problem that the house isn't warm enough? If so, it may just be that you need to set the thermostat higher.

I'll try to go through the rest logically and methodically!

there's only the option to pre set 2 temperatures, ie one for "eco" and one for "comfort"

Do you want more than two temperatures? More can sometimes be confusing.

I also noticed that we either have cold or hot radiators and nothing in-between .

Is that different to the Salus?

I've discovered that the Salus had opentherm technology which was compatible with our Baxi modulating boiler.

Were you using OpenTherm with the Salus? It may not have been connected.

The best temp control and " comfort" we had was when the Salus wasn't working and we had the receiver on manual and the flow temp on the boiler at around 55c first thing in the morning for 2 hrs, 40c for the rest of the day till about 22 30 and about 20c overnight.
Maintained the temp in the house at between 19.5 and 20c and temp at midnight was 19c and 17.5-18c at 0800 when we'd get up to turn the flow rate up to 55c.

That's a bit like how OpenTherm works. It varies the flow temperature to maintain the room temperature, rather than turning the boiler on/off. What flow temperature are you using now? Was it the same when the Salus was working?

Not been that happy with it as the optimisation mode doesn't seem to work

In what ways doesn't it work? Is your house too cold in the morning?

Somewhat p..d off that he fitted this , especially when the stat " optimisation" mode doesn't seem to work..I set it ( in opti comfort mode) to be 20c at 0900 today and the boiler didn't fire up till 0900 so it was still only 18c when we got up.

You could just set the comfort period to start a bit earlier and not rely on optimisation.

And the other thing I'm curious about is something that the Salus called " span" which could be set to either 0.5 or 0.25 ( °c)
No such info about the Neomitis but reading around maybe it's 1c ?
No wonder we're feeling chilly

What was your Salus model. You said previously RT50RF, but did you actually mean either RT500RF or RT510RF? They have different settings for SPAN. By default the Neomitis doesn't use SPAN, it uses an algorithm called TPI, which works in a different way, to give better control of temperature. It can be altered to use SPAN, but that's unlikely to have been done.

The new Neomitis is just an "on" " off" control which surely defeats the object of having a modulating boiler?
I'm reading that by modulating the boiler is more efficient and by reducing the flow rate it also reduces wear and tear on the boiler.

The boiler can still modulate with an on/off control. But probably not as much as with OpenTherm. With on/off thermostat, as the boiler gets closer to its set temperature, it will modulate down to try not overshoot its set temperature. It gets very complicated because there are two competing factors. You have the boiler cycling on/off because it's reached its set temperature, and you have the thermostat using its TPI algorithm to deliberately cycle the boiler on/off. Does the thermostat reaches its set temperature during the day?

 

[whatsthenews]

Is the overall problem that the house isn't warm enough? If so, it may just be that you need to set the thermostat higher.

Thank you for breaking it all down!
Seems I'm a dim wit as I can't see anything in the don't think the boiler ( a Potterton Titanium 28) does have opentherm , but it is fully modulating.
Too much going on in the elderly parents department ATM and feeling somewhat , but I'll attempt to answer to the best of my brain power!

The house feels warm in the morning when the radiators are on at much full tilt before it reaches the set temp of 20c. It doesn't appear to "overshoot" .
I've never seen the room temp drop below 20c today, but as the day's gone on the house has felt much cooler , especially downstairs.
At one point when I saw the flame sign on ( room temp still 20c) , I felt the radiators and they were cold so I shot into the garage and the temp on the boiler was 28/29, so it had obviously just fired up.
It barely reached the set temp ( 50c ) before it switched off. The radiators were only slightly warm at the top .

Do you want more than two temperatures? More can sometimes be confusing.

Not too bothered for us , but could have done with it my elderly mother as she can't compute thermostats, radiators etc anymore and has a tendency to wack the thermostat up to 22c if the radiators aren't warm/ hot at 7am and then go back to bed till 9am, and if they aren't on then , regardless of the room temp, wack it up again We had an overnight temp of 19c, early am of 20.5, late morning shower time 22.5, lunch till bed 21.5 to try and stop her moving the thermostat about and turning it up.

Is that different to the Salus?

With the Salus it seemed like the radiators were constantly at least a little warm during the day and the boiler was modulating because the pump would s be running but the burner would turn off before the boiler temp reached whatever it was set to. It seemed to fire up more often but for shorter periods. The problem might be that we had a very cold spell last week , but now it's quite mild, plus we had our "toasty" spell without a 'stat ( except using it as a thermometer) , so maybe I just got used to warm rad's giving heat off.

That's a bit like how OpenTherm works. It varies the flow temperature to maintain the room temperature, rather than turning the boiler on/off. What flow temperature are you using now? Was it the same when the Salus was working?

Well , as I said , it seems our boiler doesn't have opentherm so it must have been just the boiler modulating .
Earlier today I had it at about 50c , but I turned it up to 60c and the stat up to 20.5. The radiators got hot!
The stat stopped calling for heat even though the room temp was still saying 20c, but then the room temp went up to 20.5c

What was your Salus model. You said previously RT50RF, but did you actually mean either RT500RF or RT510RF? They have different settings for SPAN. By default the Neomitis doesn't use SPAN, it uses an algorithm called TPI, which works in a different way, to give better control of temperature. It can be altered to use SPAN, but that's unlikely to have been done.

Sorry if I said that . It was the RT520RF.
Yes I had the span set at .25c and the TPI was set to radiators? So you're saying it's either / or ? I can see why ...
The Salus , like the Neomitis , also had optimisation, but I could never get it to work on that either!
TPI is "on" on the Neomitis

In what ways doesn't it work? Is your house too cold in the morning?

I understand that if optimisation is "on" and I set comfort period 1 start to 0900 with the comfort temp set at 20c, the idea is that the heating will come on before 0900 to attempt to have the house at 20c at 0900?
I had it on opti comfort and the boiler must only have come on at 0900 as the room temp was only saying 18.5 at 0910.
It's set on Auto . I assume that in Auto with time 3 ending at 2300, overnight it goes to Eco (which is set at 18c ) ?
I've just set start 1 to 0815 now and even though it's in Opti comfort it comes on at 0815.

I'll see what it's like over the next week or so . I'm less annoyed now that I ( think) know the boiler isn't opentherm.

Thanks for taking the time to help .

 

[JonathanM]

Seems I'm a dim wit as I can't see anything in the don't think the boiler ( a Potterton Titanium 28) does have opentherm

I don't know whether it has OpenTherm, either! Nothing comes up when Googling, though.

The house feels warm in the morning when the radiators are on at much full tilt before it reaches the set temp of 20c. It doesn't appear to "overshoot" .
I've never seen the room temp drop below 20c today, but as the day's gone on the house has felt much cooler , especially downstairs.
At one point when I saw the flame sign on ( room temp still 20c) , I felt the radiators and they were cold so I shot into the garage and the temp on the boiler was 28/29, so it had obviously just fired up.
It barely reached the set temp ( 50c ) before it switched off. The radiators were only slightly warm at the top .

That all sounds like the TPI is working normally and doing a really good job of keeping the temperature very stable at 20C. I've noticed that it sometimes feels warmer than indicated when the radiators are on high. I think it might be the convection current warming you.

Is the sun playing a factor at all in warming you in the morning?

TPI is designed to come on several times an hour, just for a few minutes, to keep things steady.

Not too bothered for us , but could have done with it my elderly mother as she can't compute thermostats, radiators etc anymore and has a tendency to wack the thermostat up to 22c if the radiators aren't warm/ hot at 7am and then go back to bed till 9am, and if they aren't on then , regardless of the room temp, wack it up again We had an overnight temp of 19c, early am of 20.5, late morning shower time 22.5, lunch till bed 21.5 to try and stop her moving the thermostat about and turning it up.

I can definitely see the issue there. Did your mother used to have a Salus as well? Was hers broken too?

With the Salus it seemed like the radiators were constantly at least a little warm during the day and the boiler was modulating because the pump would s be running but the burner would turn off before the boiler temp reached whatever it was set to. It seemed to fire up more often but for shorter periods. The problem might be that we had a very cold spell last week , but now it's quite mild, plus we had our "toasty" spell without a 'stat ( except using it as a thermometer) , so maybe I just got used to warm rad's giving heat off.

It sounds like the Salus was using TPI as well. That would normally be the default. The "radiator" setting means it would be using 6 cycles per hour. So it sounds like, before it broke, it was working normally. The new thermostat may be designed to use fewer cycles per hour and therefore burning longer each time, then going cold in between.

Earlier today I had it at about 50c , but I turned it up to 60c and the stat up to 20.5. The radiators got hot!
The stat stopped calling for heat even though the room temp was still saying 20c, but then the room temp went up to 20.5c

Most people wouldn't make the effort to manage the boiler temperature manually like that. But it certainly worked. TPI tries to predict what the temperature will end up at and cut off early so it doesn't overshoot. It seems to be working very well.

Sorry if I said that . It was the RT520RF.
Yes I had the span set at .25c and the TPI was set to radiators? So you're saying it's either / or ? I can see why ...

It's normally either/or on Salus thermostats, but reading the manual just now, that model is a bit confusing. It's nothing to worry about though. The new thermostat seems to have excellent temperature control.

I understand that if optimisation is "on" and I set comfort period 1 start to 0900 with the comfort temp set at 20c, the idea is that the heating will come on before 0900 to attempt to have the house at 20c at 0900?
I had it on opti comfort and the boiler must only have come on at 0900 as the room temp was only saying 18.5 at 0910.
It's set on Auto . I assume that in Auto with time 3 ending at 2300, overnight it goes to Eco (which is set at 18c ) ?

That's how it looks to me from reading the manual, for all of those settings.

 

[whatsthenews]

Thank you
I think you're correct about it feeling warmer when the rads are convecting ,regardless of the room temperature on the stat.
And yes, maybe the Neomitis does have fewer cycles on tpi. I'll try and take note. More difficult with the boiler in the garage

The Salus instructions were somewhat confusing

My mother had a Danfoss. I can't recall which model it was. It was working, but we know that at some point she'd dropped it and there was an intermittent fault with the display disappearing.
We could have coped with it, but she couldn't and would call us to go and sort it out. We're past the stage of being able to give instructions over the phone as she has some memory and understanding problems etc. We were worried that it would pack up completely.
They have a Vaillant boiler. Can't recall the model, but it definitely modulates as when they first moved there, having no experience of them, I wondered why the boiler temp wasn't going up to the max setting sometimes and looked it up.

We get the sun (what's that?. We're in the NE!) in the back of the house in the morning and it makes a very noticeable difference. Our main bathroom has 2 outside walls and 2 windows. Just swapped out a large heated towel for a double, double convector so it's warm now first thing at least , but for the rest of a non sunny day it's cool/ cold. With the stat on 20c on a milder , cloudy day the radiator never really gets hot enough to convect.
We probably should have had some UFH or an electric towel rail put on when we had it redone.

Thanks again . I'm now clearer on TPI etc and understanding why we might be noticing a difference..

 

[ianmcd]

your boiler is 240V switching it does not support open therm

 

[whatsthenews]

your boiler is 240V switching it does not support open therm

Thank you for clearing it up