Boiler water temp

matelodave

TBH the precise temperature is probably irrelevant and the optimum will be different for almost everyone depending on their circumstances and heating system

IMO the best way to adjust it is to turn the temp down, say 5-10 degrees  and see how the system performs and keep turning it down a bit.until it either takes an inordinate time to reheat the place or the place doesn't get warm enough. Then increase it by just a degree at a time until it's about right.

You do need to let the system to settle for a day or two between adjustments but the aim is to optimise the flow temp to the lowest you can get away with. A lot will also depend on whether you want a one hour blast when you get uo before you go to work and then a few hours in the evening when you get home or whether you are at home all day and the heating can idle away to maintain a fairly even temperature throughout the day.

Its also a good idea to try and monitor the energy consumption to see how the tweaking affects consumption

[Deleted User]

matelodave said:

TBH the precise temperature is probably irrelevant and the optimum will be different for almost everyone depending on their circumstances and heating system

IMO the best way to adjust it is to turn the temp down, say 5-10 degrees  and see how the system performs and keep turning it down a bit.until it either takes an inordinate time to reheat the place or the place doesn't get warm enough. Then increase it by just a degree at a time until it's about right.

You do need to let the system to settle for a day or two between adjustments but the aim is to optimise the flow temp to the lowest you can get away with. A lot will also depend on whether you want a one hour blast when you get uo before you go to work and then a few hours in the evening when you get home or whether you are at home all day and the heating can idle away to maintain a fairly even temperature throughout the day.

Its also a good idea to try and monitor the energy consumption to see how the tweaking affects consumption

Turning down the boiler flow temperature also works in a home with a HW cylinder provided that the cylinder temperature is set to a figure below that our the boiler. FWiW, I run my boiler at 55C and heat my HW cylinder at the same time as I am charging my EV.

Running a boiler at a lower temperature is also an indication as to whether a heat pump would work without too many changes.

roddydogs

Always have mine at 75max, want quick heat up and water, cost is negligible.

matelodave

[Deleted User] said:

matelodave said:

TBH the precise temperature is probably irrelevant and the optimum will be different for almost everyone depending on their circumstances and heating system

IMO the best way to adjust it is to turn the temp down, say 5-10 degrees  and see how the system performs and keep turning it down a bit.until it either takes an inordinate time to reheat the place or the place doesn't get warm enough. Then increase it by just a degree at a time until it's about right.

You do need to let the system to settle for a day or two between adjustments but the aim is to optimise the flow temp to the lowest you can get away with. A lot will also depend on whether you want a one hour blast when you get uo before you go to work and then a few hours in the evening when you get home or whether you are at home all day and the heating can idle away to maintain a fairly even temperature throughout the day.

Its also a good idea to try and monitor the energy consumption to see how the tweaking affects consumption

Turning down the boiler flow temperature also works in a home with a HW cylinder provided that the cylinder temperature is set to a figure below that our the boiler. FWiW, I run my boiler at 55C and heat my HW cylinder at the same time as I am charging my EV.

Running a boiler at a lower temperature is also an indication as to whether a heat pump would work without too many changes.

I do have a heatpump, underfloor heating and a hot water tank heated from the heatpump..

The heatpump has weather compensation and idles away for most of the day and night at around 28-35 degrees keeping the our bungalow nice and warm. There are occasional excursions to nearly 40 when the outside temp drops to zero or below but over time I've reduced the weather compensation slope to keep the room temperatures to around 19-20 degrees.. Having a warm floor all over means that we don't need red hot radiators and there are no cold draughts or cold spots

Because we are at home all day we don't need a short term boost in the mornings and evenings but do back off the flow temp by 3 degrees overnight.

The unit uses a lot more energy when set to a fixed temperature or when  the room stats cause it to cycle on an off rather than let it idle at a low temperature during the day. The only drawback is that the system is slow to reheat the place if we let it get stone cold

Our hot water tank is set to 45 degrees which is more than hot enough for our needs (it does get a boost once a week to 60 for legionella sterilisation)

BikingBud

matelodave said:

[Deleted User] said:

matelodave said:

TBH the precise temperature is probably irrelevant and the optimum will be different for almost everyone depending on their circumstances and heating system

IMO the best way to adjust it is to turn the temp down, say 5-10 degrees  and see how the system performs and keep turning it down a bit.until it either takes an inordinate time to reheat the place or the place doesn't get warm enough. Then increase it by just a degree at a time until it's about right.

You do need to let the system to settle for a day or two between adjustments but the aim is to optimise the flow temp to the lowest you can get away with. A lot will also depend on whether you want a one hour blast when you get uo before you go to work and then a few hours in the evening when you get home or whether you are at home all day and the heating can idle away to maintain a fairly even temperature throughout the day.

Its also a good idea to try and monitor the energy consumption to see how the tweaking affects consumption

Turning down the boiler flow temperature also works in a home with a HW cylinder provided that the cylinder temperature is set to a figure below that our the boiler. FWiW, I run my boiler at 55C and heat my HW cylinder at the same time as I am charging my EV.

Running a boiler at a lower temperature is also an indication as to whether a heat pump would work without too many changes.

I do have a heatpump, underfloor heating and a hot water tank heated from the heatpump..

The heatpump has weather compensation and idles away for most of the day and night at around 28-35 degrees keeping the our bungalow nice and warm. There are occasional excursions to nearly 40 when the outside temp drops to zero or below but over time I've reduced the weather compensation slope to keep the room temperatures to around 19-20 degrees.. Having a warm floor all over means that we don't need red hot radiators and there are no cold draughts or cold spots

Because we are at home all day we don't need a short term boost in the mornings and evenings but do back off the flow temp by 3 degrees overnight.

The unit uses a lot more energy when set to a fixed temperature or when  the room stats cause it to cycle on an off rather than let it idle at a low temperature during the day. The only drawback is that the system is slow to reheat the place if we let it get stone cold

Our hot water tank is set to 45 degrees which is more than hot enough for our needs (it does get a boost once a week to 60 for legionella sterilisation)

@matelodave
Perhaps you could try and explain this to some on the myth busting thread, the closed minds stick to physics principles rather than reality of operation and the fact that low temp idle can provide a comfortable environment.

BUFF

matelodave said:

Its also a good idea to try and monitor the energy consumption to see how the tweaking affects consumption

absolutely but you do need a way of normalising for the differing weather day to day outside & the effect that has on the building fabric & therefore demand (this will, of course, vary building to building).

Northern_Wanderer

Probably the 50C advice from Octopus is written by someone that knows less about flow temp than me! Just an attempt to make it look like they are doing something to help people maybe use less gas?

As my boiler is in the loft, the flow has to come down to the first floor, down to the ground floor and back to the loft. It's a 3 bed, 9 rads. How much lower is my return temp likely to be than the boiler flow temp? Any ideas?

BUFF

Northern_Wanderer said:

As my boiler is in the loft, the flow has to come down to the first floor, down to the ground floor and back to the loft. It's a 3 bed, 9 rads. How much lower is my return temp likely to be than the boiler flow temp? Any ideas?

There are lots of variables in how it (& your house heating system) may run. You can buy pipe thermometers inexpensively (or your boiler commissioning sheet may give it).

Verdigris

Northern_Wanderer said:

Probably the 50C advice from Octopus is written by someone that knows less about flow temp than me! Just an attempt to make it look like they are doing something to help people maybe use less gas?

As my boiler is in the loft, the flow has to come down to the first floor, down to the ground floor and back to the loft. It's a 3 bed, 9 rads. How much lower is my return temp likely to be than the boiler flow temp? Any ideas?

Measure it. You can get an electronic thermometer for a couple of quid. Tape the thermocouple to each pipe, near the boiler, in turn and see what the differnece is.

Northern_Wanderer

Verdigris said:

Measure it. You can get an electronic thermometer for a couple of quid. Tape the thermocouple to each pipe, near the boiler, in turn and see what the differnece is.

Thanks, I will check those thermometers out.