Money Saving Boiler Challenge - Turn down boiler temp to save money and energy waste

ariarnia

BUFF said:

ariarnia said:

manamaga2512 said:

Leon_W said:

Just to help you get your head around boilers at lower temperatures and heat up times.

It's exactly the same concept as driving a car economically.  If you accelerate away from traffic lights with your foot flat to the floor to 50mph you are going use way more petrol than accelerating gently to 50mph.  The end result is the same, 50mph but doing so as economically as possible.

So, running your boiler at a lower flow rate temperature will still achieve the same desired room temperature but it will just take longer to get there.

Yep, I get that, cheers. So what you're saying is despite the manufacturer guidance of using the eco mode on the boiler to use less energy.....ignore that and still turn down to 60?
This is my main issue of conflicting information. I mean surely the people best placed to advise on the best energy performance is the people who make the boiler? I dunno.

i think theres a difference between a general 'works for anyone' option and works for your system in your house. the boiler will use the least gas on eco mode in a lab. but your house has a different number of radiators and amount of insulation than the lab set up (probably) so you should really play around with your boiler and see. 

i had a similar conversation with our washing machine manufacturers as their eco setting is recommended to use the least water and power but it only takes 4kg. so the 9kg wash turned down to 40 uses less power and water than running the eco mode twice. 

but the reason i was on this thread was to ask how those of us without a fancy display telling the return temp could work it out. we dont use our boiler much as we have a stove in the lounge but we this weekend we were doing our annual 'testing' to check it still works (our local plumber comes in june to check it's safe but we like to check around this time that there's no cold spots in the rads or anything). one thing i have noticed is that with our condensing boiler if i turn the temp down i don't see steam coming out of the exit pipe. does that mean it's condensing in the boiler and is a good thing? 

You can get thermometers that strap to pipes if you want a  permanent install or can use a contact thermometer.
& yes, if you aren't seeing steam from the flue it is either that the exhaust is so hot that it isn't condensing into visible vapour anywhere near the flue or it has already condensed within the flue. The latter would be a good thing .

i wouldnt know which pipe to attach it to. knowing me i'd put it on the water main

thank you. i will be reassured that we're more likely condensing than not. 

Astria

Spies said:

Here's my flow and return graph for my Worcester Bosch 29cdi set at ~60c

The thermostat cycles the boiler a max of 6 times per hour for a minimum of 1 minute at a time.

Bit's with no return rise when flow does, is DHW demand.

Interesting no?

When I checked mine the other day, the output temperature was 67c and the return 43c, the boiler managed to maintain 67c for the duration of the time the heating was on (37 minutes according to HIVE). The house was at 15c when it started and 17c when it finished.

If I just put the hot water tank on, then the boiler can very quickly hit 69c and shutdown, turning back on when it hits about 43c, it seems particularly inefficient at doing this as an hour later it's still trying to get the tank to the target temperature of 60c, seems much better if it comes on at the same time as the heating.

Ultrasonic

Leon_W said:

It's exactly the same concept as driving a car economically.  If you accelerate away from traffic lights with your foot flat to the floor to 50mph you are going use way more petrol than accelerating gently to 50mph.  The end result is the same, 50mph but doing so as economically as possible.

This is actually a flawed analogy as car engines are typically most efficient (most power per unit of fuel used) under relatively hard acceleration. See e.g. https://en.wikipedia.org/wiki/Brake-specific_fuel_consumption

The way to get to 50 mph using as little fuel as possible is not to accelerate as slowly as possible. However, slow acceleration may result in less total fuel used by virtue of the average speed being lower.

Ally_E.

I have a system boiler. I have alarms on my phone to turn up the flow temp when water is scheduled to heat and then turn it down before I turn the heating on. It works for me with a 10 year old condensing boiler.