CH not getting to temp like it used to.

[6moe66]

Hey all,

After a search on the forum i couldnt find anything so though id ask you kind souls.

After installing Drayton Wiser smart thermostat and TRVs to the Ideal Logic + 35, the CH temp doesnt get above 45degrees.

The boiler itself has a temp dial which will go from 45-83degrees for required CH output but this does nothing to the output when altered, even though it will show on the led panel it is changing.

Display on boiler now shows
HIGH EFFICIENCY CENTERAL HEATING 45° CONTROLLED BY ROOM STAT. and by touching the CH output pipe its definitely not as hot as it used to be.

Open therm was activated when the smart thermostat was installed.

Thanks and any tips on how to get the CH back up to temperature before the mrs has to put on a jumper would be much apreciated

 

[snowhead]

What's the thermostat set to and is it in a room with TRV on the radiator now?
The stat is running the boiler in Opentherm, at the lowest possible flow temp.

 

[Gasmk1]

It is running the boiler at its most economical you probably do not have the heating on long enough like most people they think 1 hour in the morning and 3 or 4 at night is enough but this never heats up the house fabric and maintains a comfort level this is why weather compensation the boiler should be on all day and on lower temp at night.

 

[Gasmk1]

It is running the boiler at its most economical you probably do not have the heating on long enough like most people they think 1 hour in the morning and 3 or 4 at night is enough but this never heats up the house fabric and maintains a comfort level this is why weather compensation the boiler should be on all day and on lower temp at night.

 

[Welder]

GasMk1
I'm intrigued. What does weather compensation do, and why should the boiler be on all day and all night?

 

[6moe66]

It is running the boiler at its most economical you probably do not have the heating on long enough like most people they think 1 hour in the morning and 3 or 4 at night is enough but this never heats up the house fabric and maintains a comfort level this is why weather compensation the boiler should be on all day and on lower temp at night.

What's the thermostat set to and is it in a room with TRV on the radiator now?
The stat is running the boiler in Opentherm, at the lowest possible flow temp.

Thanks for the replies.

I run the timer to come on for 3hrs in the morning and 6hours again at night at 22° with 16° being the ambient minimum set point.

The Room stat is in the same room as the smart TRV(livingroom) and use that to boost the CH in the whole house when needed. If only one room needed then will only turn the TRV in that room to fire the boiler for that room only.

I get if the heating isnt on for long enough then the room will not reach the required temperature but i know the CH tempetature is being limited to 45° as prior to installing the new Drayton Wiser System, the radiators were almost too hot to touch and the CH temp was pumping out what ever temp i had set it to on the boiler.

I would like to increase the temperature output of the boiler which appears to be limited by the room stat or at least understand how the stat is working as the radiators are only ever mildly warm and this is not enough to heat the house.

Any suggestions are welcome and thanks again for your time to reply.

 

[Gasmk1]

GasMk1
I'm intrigued. What does weather compensation do, and why should the boiler be on all day and all night?

its not on all day and all night true weather comp runs the boiler at a low temperature correlating the heat loss from the heating to the house with the outside temperature giving ideal comfort conditions. you run the night time at a lower temperature. it allows the fabric of the house to warm up so in effect you dont use as much energy.
How does it work?
A small temperature sensor is located on the outside of the building, on a north facing wall. This is wired to the internal controls of the boiler and information about the outside temperature is sent to the boiler controller constantly.
When the temperature changes outside the boiler responds and starts to increase or decrease the radiator temperature to compensate.
This pro-active mechanism means that people inside the building won't even notice that the temperature has changed outside.
For example, when the outside temperature drops at night, more heat is lost through the walls of the building.
Because the outdoor sensor detects the fall as soon as it happens, the boiler is able to raise the radiator temperature and keep the inside temperature stable.
With a conventional system, the temperature is dependent on a room thermostat, which will only take effect after the inside of the building has become too hot or too cold.
In summary, weather compensation controls enable the boiler to respond to outside temperature changes and adjust the radiator output, to maintain a constant temperature indoors. i had a viessmann 200 combi in my last house fitted with weather comp and my bills were greatly reduced . the nightime temperature you set lower than daytime.

 

[townfanjon]

i had a viessmann 200 combi in my last house fitted with weather comp and my bills were greatly reduced .

The 200’s with WC are incredible, I had a CPC done on our house back in the summer and the surveyor wouldn’t believe me when I told him how much our gas bill was, I ended up printing him an annual energy usage sheet off BG to prove it .

 

[Gasmk1]

The 200’s with WC are incredible, I had a CPC done on our house back in the summer and the surveyor wouldn’t believe me when I told him how much our gas bill was, I ended up printing him an annual energy usage sheet off BG to prove it .

i fitted a 4 pipe 100 in a customers house with weather comp she couldnt beleive how much she was saving and that was even during summer hot water only her old boiler must have been using a lot she sang its praise to all her friends.

 

[6moe66]

What's the thermostat set to and is it in a room with TRV on the radiator now?
The stat is running the boiler in Opentherm, at the lowest possible flow temp.

I've put the thermostat in the coldest part of the house and tried to demand max room temp (30°) but still no change. And also removed the wireless room stat completely from the setup on the app. The boiler still states HIGH EFFICIENCY CENTERAL HEATING 45° CONTROLLED BY ROOM STAT.

I do not have an outdoor sensor fitted. Only opentherm.

Any ideas?

 

[sammathias]

It's connected by opentherm so its not going to dish out high flow temperatures that your used too. Drayton will be able to explain it better if you give them a call/email.

 

[fezster]

The drayton wiser system should adjust the flow temp using opentherm depending on the delta T between the room and thermostat. With Evohome, for example, if the delta T exceeds a few degrees, the flow temp is set to MAX.

I don't know enough about your boiler or wiser to advise further, but it's worth checking if there is some setting on the boiler which limits the max temperature allowed.

I'd also give the Wiser helpline a call. They may be able to tell you if it's possible to monitor what flow temp is being requested by Wiser using their app.

Failing all of the above - it may be a faulty unit. The other option, of course, is to not use opentherm and link up Wiser to your boiler in the traditional way.