Combating energy prices

@Manbatius just did the same. Not difficult to switch on when needed and don’t need the clock. Two microwaves switched off. I wonder whether it’s worth having the cooker/oven left on?

I wonder how much less energy we’ll use as a country now everyone is thinking about this. It soon adds up.

andy_mk3 said:
If you have a Combi boiler you can set the hot water quite low, it should help a little with energy usage. As the water isn't being stored there's no risk from the lower temperature unlike a tank. Ours is set to 45C on the boiler and its ideal for what we use it for, which is pretty much just the bath or shower. Saves on mixing it down so much.
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I’ve done this with our boiler. No point heating water to just mix it with cold water. We do have a tank, but it still doesn’t need to be as high.
 
The only benefit for washing your hands with warm water is comfort. The water isn’t hot enough to do anything else. If anything it’s in the danger zone for bacterial growth.

You even put your hand under 60+c water without being scalded.
 
b0rn2sk8 said:
The only benefit for washing your hands with warm water is comfort. The water isn’t hot enough to do anything else. If anything it’s in the danger zone for bacterial growth.

You even put your hand under 60+c water without being scalded.
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I only recently realised some people even use the hot tap for washing their hands as I noticed my girlfriend do it. I'd always wondered why I heard the boiler fire up when she was in the bathroom.

I literally don't use the hot tap at the sink unless I'm shaving!
 
CaptainRAVE said:
@Manbatius just did the same. Not difficult to switch on when needed and don’t need the clock. Two microwaves switched off. I wonder whether it’s worth having the cooker/oven left on?

I wonder how much less energy we’ll use as a country now everyone is thinking about this. It soon adds up.



I’ve done this with our boiler. No point heating water to just mix it with cold water. We do have a tank, but it still doesn’t need to be as high.
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A water cylinder needs to be 60c to kill off legionnaires unlike a combi that doesn’t have a cylinder.
 
Mickie said:
A water cylinder needs to be 60c to kill off legionnaires unlike a combi that doesn’t have a cylinder.
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The problem with a boiler that just has a hot water setting of 1-5 it’s difficult to workout what temperature that equates to. I’m pretty sure the hot tap on full is far higher than 60C.
 
CaptainRAVE said:
The problem with a boiler that just has a hot water setting of 1-5 it’s difficult to workout what temperature that equates to. I’m pretty sure the hot tap on full is far higher than 60C.
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Get a thermometer and measure the water coming out on full on hot closest to the boiler.
 
squerble said:
Another good tip is to just use cold water when you wash your hands after using the loo.
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I've pretty much always done this, I never understood why people used hot water, especially when you have decent soap. Unless you have really dirty/greasy hands from working on car/bike etc of course, it's not worth it.
 
Usually don't empty washing up bowl in kitchen(after breakfast), or, can leave sink in bathroom half full to provide for washing hands later in day.

combi boiler directly heating water
since with direct heating there is no efficiency benefit from the lower temperature output that provides condensing benefit for heating loop, ours is just at 60C,
which provides some margin if someone tries to use hot tap whilst someone is having a shower,
otherwise don't see much point in reducing it for a marginal gain of running lower temperature water through pipe run with less cold finally mixed in.

with combi boiler directly heating water the highest temperature is usually on partial flow, and, with tap full on the temperature drops, since it's not powerful enough.
( you'd need a 50Kw boiler to provide a shower at 14L/min 70C )
 
CaptainRAVE said:
The problem with a boiler that just has a hot water setting of 1-5 it’s difficult to workout what temperature that equates to. I’m pretty sure the hot tap on full is far higher than 60C.
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I don't think modern combi boilers will operate much above 60C as there's no domestic use case for anything higher; that's what the kettle is for. :)

60C from your hot tap will have vapour and a level of heat that seems like a higher temperature because you won't be able to hold your hand under it.
 
Mickie said:
A water cylinder needs to be 60c to kill off legionnaires unlike a combi that doesn’t have a cylinder.
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No cylinder but a small on-board tank in some cases. Our combi has a "domestic water pre-heat" option which keeps a small amount of water in it at 60ºC meaning you get hot water at the tap a lot faster... but seems like a huge waste of gas to have it firing up every 60-90 minutes to top up that heat.
 
squerble said:
No cylinder but a small on-board tank in some cases. Our combi has a "domestic water pre-heat" option which keeps a small amount of water in it at 60ºC meaning you get hot water at the tap a lot faster... but seems like a huge waste of gas to have it firing up every 60-90 minutes to top up that heat.
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Just like a cylinder keeping the boiler pre heated will leak Energy.. I've started washing my hands with cold water, just using the hot water for showers.
 
jpaul said:
Usually don't empty washing up bowl in kitchen(after breakfast), or, can leave sink in bathroom half full to provide for washing hands later in day.

combi boiler directly heating water
since with direct heating there is no efficiency benefit from the lower temperature output that provides condensing benefit for heating loop, ours is just at 60C,
which provides some margin if someone tries to use hot tap whilst someone is having a shower,
otherwise don't see much point in reducing it for a marginal gain of running lower temperature water through pipe run with less cold finally mixed in.

with combi boiler directly heating water the highest temperature is usually on partial flow, and, with tap full on the temperature drops, since it's not powerful enough.
( you'd need a 50Kw boiler to provide a shower at 14L/min 70C )
Click to expand...

But why would you heat water up to 60C if you don't need it? That's additional energy.
 
dirtychinchilla said:
But why would you heat water up to 60C if you don't need it? That's additional energy.
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if you want 70L of water at 40C for your shower, then heating 70L from (say) 20C-> 40C needs same energy as heating 35L from 20-60C and mixing it down at the tap;

might be some additional heat loss/radiation from the hot pipe running at the higher 60C.

(non-pumped) shower is upstairs & boiler downstairs, so maybe able to get better flow using both hot&cold pipes as opposed to just hot w/o mixing (@40C) <<< not 100% sure that is true ?

running boiler at higher temperature may mean it uses a bit more energy when it cools/purges the heat exchanger when shower is done.


squerble said:
... but seems like a huge waste of gas to have it firing up every 60-90 minutes to top up that heat.
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yes I turn off pre-heat outside of breakfast/evening-meal/shower times - if I get a smart meter I'll figure out how much gas the pre-heat uses.
 
jpaul said:
if you want 70L of water at 40C for your shower, then heating 70L from (say) 20C-> 40C needs same energy as heating 35L from 20-60C and mixing it down at the tap;

might be some additional heat loss/radiation from the hot pipe running at the higher 60C.
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Sure, if you reduce the flow rate to 50% for the latter.
 
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