Gas Central Heating Zone Question

Shane732

So I've a bit of a stupid question -

I have a gas boiler with 2 zones - one zone being water only and the other being rads and water.

I no longer need the rads now and am putting it to water only. So my question - do I need to have the boiler on less to heat the water only or does the boiler use less gas but stay on for the same amount of time?

Dtp1979

Shane732 wrote: »

So I've a bit of a stupid question -

I have a gas boiler with 2 zones - one zone being water only and the other being rads and water.

I no longer need the rads now and am putting it to water only. So my question - do I need to have the boiler on less to heat the water only or does the boiler use less gas but stay on for the same amount of time?

Depending on what boiler you have and how it's wired. Open the balance valve fully for the summer months. If there's a thermostat on the cylinder it should, by right, turn the boiler off when the water is 60 degrees

CloughCasey1

Shane732 wrote: »

So I've a bit of a stupid question -

I have a gas boiler with 2 zones - one zone being water only and the other being rads and water.

I no longer need the rads now and am putting it to water only. So my question - do I need to have the boiler on less to heat the water only or does the boiler use less gas but stay on for the same amount of time?

Have you a thermostat on cylinder? When you time the boiler for hour in morning and hournin evening to heat the water it will only come in for a short period of time compared to a full rad and clyinder heating for the winter. Make sure your cylinder thermostat is set to 60degrees plus to prevent legionnaires. If the stat on cylinder hits the 60 degree mark before the end of the hour that the time is set it should automatically shut down the boiler. An efficient gas boiler should be cheaper to heat the water than a immersion un summer. Also immersions are usually set to heat water to 90 degrees which can scald especially with children.

freddyuk

CloughCasey1 wrote: »

Have you a thermostat on cylinder? When you time the boiler for hour in morning and hournin evening to heat the water it will only come in for a short period of time compared to a full rad and clyinder heating for the winter. Make sure your cylinder thermostat is set to 60degrees plus to prevent legionnaires. If the stat on cylinder hits the 60 degree mark before the end of the hour that the time is set it should automatically shut down the boiler. An efficient gas boiler should be cheaper to heat the water than a immersion un summer. Also immersions are usually set to heat water to 90 degrees which can scald especially with children.

You will instantly boil your children at 90c. Immersions are now limited to 60c in most cases (although older ones will go much higher) but this is also very hot for DHW if there are children involved. A cylinder stat is located 2/3 down the cylinder so setting this at 60c+ is going to cause the outlet to be 70c+ which requires a thermostatic mixing valve to be safe or you will be scalding everyone that opens the hot tap.
At the bottom of the cylinder it will be 25-35c so the legionella is all at the bottom where it is safe. So that's good.....;)

Shane732

I don't have a cylinder stat.

So basically if I don't have a cylinder stat the boiler will just run and keep heating the water meaning the cost of heating the water should be the same as heating the water and the rads? I.e. the boiler is running for the same amount of time.

Just listening to the boiler it doesn't appear to be clicking in as often but I definitely don't have a cylinder stat.