Possibly a rather dappy question but should I adjust the temperature
of my hot water using the dial on the boiler itself (graded at 'cold',
'warm', 'warm/hot', 'hot') or a dial I've noticed on the hot water
tank which looks to be graded in degrees C.
Just moved into a new house and therefore have a new heating system to
learn the intricacies of. The (gas) boiler and hot and cold water
tanks are all up in the loft. I'm getting some spluttering problems
from the hot water, and I did see a sugestion in another thread that
turning down the hot water temp may help...
The one on your boiler affects the temperature of the water in the
circulating water that heats the radiators and the cylinder. This will cause
the radiators to change temperature. Low is efficient thermodynamically and
safer for kids. High causes more heat output.
The thermostat on the hot water cylinder determines the temperature of your
hot water. This should be set to around 55C.
However, your circulating water MUST be AT LEAST 5C more than your hot water
temperature. Otherwise, the hot water cylinder will never heat up enough to
trip the stat, which will be very inefficient, as the boiler will never turn
The boiler temperature should be set to just less than max, unless you can
spare time to experiment scientifically to ensure adequete radiator and hot
water performance, or your entire system has and is optimised for a
Thanks for the tips. That all seems to make sense.
I'll try turning the water tank thermostat down a bit and see whether
the hot water gets a bit cooler. We don't have any children but that
doesn't mean that the hot water couldn't still scald someone.
I think also I'll spend a bit of time studying the layout of pipes and
wires to try and get clear in my head how the system works.
I've lurked here for years but never needed to ask any questions. I'll
probably be back soon asking something else. :o)
Watch out though. If you have a standard size tank (900x450), you aren't
actually storing much water. By dropping the temperature, you may find you
run out of hot water in use, as you are storing less energy. If this
happens, you should fit a thermostatic mixing valve to the output, where you
can set the output temperature directly, whilst still storing the hot water
at 60C or so, which gives more stored energy and better resistance to
bacterial infection. It will also prevent boiling water being issued from
the taps in the event of an immersion or boiler thermostat failure.
Does your tank have an electric immersion heater in it? Tanks on their own
cannot of course actively heat water. Presumably your water is normally
heated from the boiler, so that is my guess as to where to adjust the
temperature. Check and see if you have an electric immersion heater in your
boiler and whether it is normally off. A lot of boilers simply try and
achieve a temperature change ( delta T ), and so the temperature of the
incoming water affects the temperature at the taps, so systems lke that need
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.