combi boiler settings - high, less time on or low, on for longer?

khampson

What is the most economical way to run my combination boiler?

The temp range for my Patterson boiler is:

Heating 25-80 degrees
Water 30-70 degrees

Am I better off setting my heating to a high setting say 80 degrees meaning it will reach the thermstat setting sooner or have it at say 60 degrees but it takes longer to reach the thermstat setting meaning the heating is on longer? What would use the less gas?

Also with the water, do I turn that up to 70 degrees then run cold water in to make it the right temperature, or run it at 50 degrees and not put cold water in?

It's more than likely been asked several times but also with many different answers but has anyone done any research in to this?

Regards Keith

brysonfire

I think we cross-posted and are having the same dilemma!

From the minimal research I've done (a few websites inc. the Energy Saving Trust) they suggest setting the water thermostat at between 55-60C, this is to prevent potentially harmful bacteria (legionella) growing in the system. Mine was set far lower than this (from summer) and I haven't died yet ;o) I turned it up to 60C and ran the tap and it seemed far too hot to me - scalding. I compromised with 55C which still seems hot. To me it would make more economical sense to only heat the water high enough to be comfortable for use, thereby also minimising cold-water use. However, I'm not sure if the risk of harmful bacteria growing makes doing this inadvisable.

The EST say that it's best to have the boiler radiator thermostat set high so that the room heats more quickly, boiler is on for less time and doesn't have to work as hard.

Room thermostats should be set at the lowest comfortable temperature. I set mine to 17.5C: it generally goes a bit higher than this before the thermostat kicks in and shuts the boiler off. I wear a jumper or fleece anyway indoors in winter so will only turn up the thermostat if I'm still really cold and a hot drink hasn't worked!

If you have your heating on constant at a low temperature, it's best to make use of your TRVs to adjust the room temperature to a comfortable level or even turn them off in rooms that aren't being used, provided the doors are shut.

khampson

brysonfire wrote: »

I think we cross-posted and are having the same dilemma!

From the minimal research I've done (a few websites inc. the Energy Saving Trust) they suggest setting the water thermostat at between 55-60C, this is to prevent potentially harmful bacteria (legionella) growing in the system. Mine was set far lower than this (from summer) and I haven't died yet ;o) I turned it up to 60C and ran the tap and it seemed far too hot to me - scalding. I compromised with 55C which still seems hot. To me it would make more economical sense to only heat the water high enough to be comfortable for use, thereby also minimising cold-water use. However, I'm not sure if the risk of harmful bacteria growing makes doing this inadvisable.

The EST say that it's best to have the boiler radiator thermostat set high so that the room heats more quickly, boiler is on for less time and doesn't have to work as hard.

Room thermostats should be set at the lowest comfortable temperature. I set mine to 17.5C: it generally goes a bit higher than this before the thermostat kicks in and shuts the boiler off. I wear a jumper or fleece anyway indoors in winter so will only turn up the thermostat if I'm still really cold and a hot drink hasn't worked!

If you have your heating on constant at a low temperature, it's best to make use of your TRVs to adjust the room temperature to a comfortable level or even turn them off in rooms that aren't being used, provided the doors are shut.

Thanks for this, I will increase my water to 55 degrees at current its only 50 degrees, unsure what to set the heating at thou, its currently 60 degrees and the maximum is 80 degrees, if you find any additional information out please let me know.

Kind regards Keith

fred7777

Keith
Re: Central Heating Temperatures
The most efficient setting for central heating temperature is the lowest temperature however this may be pointless as it won't get your house warm.
Heating systems used to be designed around boilers which produced water at 80°C and took water back in around 60°C so if you have an older system, regardless of the boiler type and age, the heating system should be set high and probably at max. I would set it high first and experiment turning it down until the system could not get the house warm.
The lower temperature settings are intended for modern oversize radiators and under floor heating which operate at much lower temperatures.