Any Boilers out there that allow flow temperature to be altered depending upon which zone is calling for heat?

[bib tap]

Ideally I would like ufh to run at 35

....but with current flow rate set at 75, the boiler aims for 75 and gets there way too fast! and overheats as the 35 mixing valve blocks most of the heat, the boiler does not like that as it over heats too much and so trips (lock out), so, I should have a buffer tank to absorb the high heat output, and the ufh can draw on it slowly, but, I don;t want one! no space for it)

Rads at 55

and hot water cylinder at 65 / 70

Possible?

I am thinking each zone would run at its most efficient with the temperatures set for each zones specific requirement, no?

thanks for any thoughts
🙂

 

[Ollieg]

Vaillant do a wiring center that allows different temperature control. I fitted one many years ago. Do some research with manufacturers, I'm sure a simple solution is out there. Or someone will have an answer for you soon.

 

[bib tap]

Vaillant do a wiring center that allows different temperature control. I fitted one many years ago. Do some research with manufacturers, I'm sure a simple solution is out there. Or someone will have an answer for you soon.

Thanks,
I did call vaillant, as I have an old ecotec plus, but they said no such tech available for their old or even their new boilers.

I was thinking there has to be a solution out there somewhere, hence the post, as I have searched and searched but only get results how to manually set the flow temp....

 

[RBG]

If I am understanding it right you want the heating flow to be a different temperature to the flow to the hot water cylinder. I.e. lower for central heating and higher to hotwater.

What you want to look at is a priority hot water boiler that has 2 different flows..one for HW and one for central heating so that you can have two different temps coming out of boiler depending on the demand. Bosch do one as to Viessman

A solution without a new boiler or one that allows for adaptation I don’t know as most boilers only have one flow temp setting on the boiler and what you want is for that to change dependant on the source of the demand. If there is a way to do it I would love to find out too.

 

[bib tap]

If I am understanding it right you want the heating flow to be a different temperature to the flow to the hot water cylinder. I.e. lower for central heating and higher to hotwater.

What you want to look at is a priority hot water boiler that has 2 different flows..one for HW and one for central heating so that you can have two different temps coming out of boiler depending on the demand. Bosch do one as to Viessman

A solution without a new boiler or one that allows for adaptation I don’t know as most boilers only have one flow temp setting on the boiler and what you want is for that to change dependant on the source of the demand. If there is a way to do it I would love to find out too.

Yes, ideally 3 variations in flow temperature, ufh 35 (most efficient temp for my ufh), rads 55 (what I believe most efficient for my boiler), hot water 65 (because we have to kill stuff).

I was coming across some posts about priority hot water, but did not quite understand it, thanks for making it clear 🙂 Yes almost there, but yes I may be more tempted for a new boiler if it did 3 flow settings rather than just 2!

Seems so weird in an AI computer based world with green issues being shoved down our throats, that they do not even make a tiny plug in for boilers that adjust the flow temp so it is run at its most efficient temperature for the application it is being used for, I mean how many stupid phone apps are there, and no boiler company thinks Ooo we could make everything run at its most efficient temp if we just did a little bit more electronics design... guess they prefer to sell heat pumps for ufh efficiency.... as gas is on the way out :-o

Lets hope someone has come across such a plug in, and lets us know :-D

Thanks for the reply!

 

[Chuck]

I'm not sure what problem you are trying to solve. If it is that you would like to run your underfloor heating (UFH) with the other zones and domestic hot water (DHW) off without the boiler 'locking out' then the following is the answer:

Modern boilers have a minimum output power limited by the need to keep the burner stable. The lowest I can recall seeing recently is around 3.5 kW from Veissmann. If the demand from the UFH is less than this the boiler will cycle on and off, usually with a period of 10 minutes, to achieve the desired average. If this cycling bothers you then you need to install a buffer tank which will increase the period.

Changing the flow temperature of the boiler won't change the minimum output.