British gas units/tarrif and Central heating controls.

Cardew

When they were changing the boiler and set to max on TRV's and boiler it would initially use a lot of gas to warm the fabric of the house; however that is not representative of normal operation/consumption.


You state that the house is not warm enough with water at 50C. So you must decide on your priorities.

roxy28

Cardew wrote: »

When they were changing the boiler and set to max on TRV's and boiler it would initially use a lot of gas to warm the fabric of the house; however that is not representative of normal operation/consumption.


You state that the house is not warm enough with water at 50C. So you must decide on your priorities.

I will try to get the best settings with trial and error , the only thing is with the boiler temp at 50 the rads are hot, not just warm, so i am thinking it may be the heat is flying out through the walls (poor insulation ).

I will get there in the end.

[Deleted User]

When you buy a radiator its kW output is based on a feed (water going into the radiator) temperature of 80C. So a system designed around an old style 80C boiler will deliver the heat the system was designed for.

When these boilers are upgraded to condensing units the boiler sets the feed water temperature such that the return (water leaving the radiator) temperature is about 50C or less to allow it to condense. This means that radiators never deliver their design output watts making rooms feel colder.

If you have single rads consider having them upgraded to double rads. This delivers more heat for a lower feed water temperature. Radiators with or without thermostatic radiator valves need balancing so that the exit temperature is lower than the input temperature. If both input and out valves are wide open it will force the boiler to output feed water at a lower temperature.

stator

See if you can find a manual for your boiler, it should state the most efficient working temperature. Some of them even have small indicators on the dial, a little star or something (not the frost indicator).

Have you bled all the radiators, topped up the pressure?

[Deleted User]

stator wrote: »

See if you can find a manual for your boiler, it should state the most efficient working temperature.

On stepped condensing boilers there is usually an Eco setting on the front panel. Stepped means that the boiler has a limited choice of settings (often four) as it tries to adjust radiator return flow temperature to keep the boiler running at the best efficiency.

Stepless boilers can adjust flow temperatures anywhere between upper and lower limits. The actual flow temperature is calculated from a computer control parameter. When an external temperature sensor is fitted the boiler flow temperature can be as low as 30C making these boilers exceptionally efficient as outside temperatures rise. Flow temperatures rise on colder days. These boilers used to be more expensive but not so much now. Plumbers usually fit stepped models unless the customer asks for stepless. Most customers and plumbers never understand the difference between the two but the right choice can save lots of money over the long term.