Main ECO compact 18 - flow temperature?

[Alistair89]

I suspect my flow temperature dial on my Main ECO compact 18 boiler is not working.

The flow temperature has always felt too high but when I turn it down the flow temperature doesn't decrease and when I turn it up it doesn't increase.

Is this normal and could the dial be at fault?

Thanks

 

[CBW]

It needs to be higher to satisfy the hot water cylinder. I doubt the dial is faulty unless you’ve measure the flow temperature?

 

[Alistair89]

Thanks.
Yes I've measured the flow temperature with an accurate temperature sensor. Flow temperature varies between 62c and 65c regardless of the dial.

My cylinder tank is set to 60c. Would that cause my boiler to send 60c flow when the system isn't heating hot water.

I agree I'm sceptical that the dial is broken but I can't seem to change the flow temperature.

My home is 1987 with 15mm copper pipe. My home has 14 radiators and I have my pump set to speed 3

I don't have any heating issues they were all sorted when I moved in, my gas engineer commented the boiler is a little undersized.

 

[CBW]

The way it works is the boiler flow temperature is higher for the cylinder to reach its temperature, and the same flow temperature is used for the heating.

 

[MNW67]

Yes I've measured the flow temperature with an accurate temperature sensor. Flow temperature varies between 62c and 65c regardless of the dial.

My cylinder tank is set to 60c. Would that cause my boiler to send 60c flow when the system isn't heating hot water.

I agree I'm sceptical that the dial is broken but I can't seem to change the flow temperature.

Your boiler dial can probably set the flow temperature anywhere from about 35C to 80C. Have you tried setting it close to the minimum? If the temperature is always at 62C to 65C, then that is obviously wrong. Unless maybe you have got either OpenTherm or weather compensation connected? If so, one of these might be controlling the flow temperature, instead of the dial on the boiler. Is there an outside sensor connected?

It looks like you have Tado?

 

[gas112]

the knobs on these have been known to pop out the board check the shaft is actually located correctly

 

[Alistair89]

I have found out the issue. I meant to take photos but after taking the front cover off and removing the control unit I found the plastic rod from the wheel was bent and not seated in the variable resistor. It must have happened when the boiler was first installed

I removed it and carefully bent it straight, once I re installed it I could tell immediately it was seated correctly.

Thanks for the replies, I am so glad I didn't call Baxi warranty without checking this first!

 

[old duffer]

combi boilers give heat priority to DHW.
Open a tap, boiler switches, gas full rate,water gets hot.
So the rate at which the boiler can heat water will be rated in the documentation e.g. 20 litres to 30 degrees. If the water flow into the heat exchanger is lower than the rated output, it will heat what passes through as it cannot check the incoming temperature or outgoing...it has a "i'd like it to be around this temp" button...not a "i want this temp and that's it" button.
My water heater does have a "i only want this temp" selector...but then again I tend towards using 21st century kit.

 

[JonathanM]

combi boilers give heat priority to DHW.

This isn't a combi.