Cold house

[IanMK13]

I moved into my present 1990-built home just over a yearago. A British Gas (Potterton) non-condensingboiler was installed a year or so before I bought the property. All the rads have TRVs and there wasoriginally just a time-switch for boiler control. Despite recently installing a programmablethermostat in place of the time switch, I am finding it impossible to maintaina comfortable temperature in many parts of the property without leaving theheating on permanently. In frostyweather, even if I set the low temperature limit at 18degC it takes hours toget back above 20degC when the thermostat changes the set point.

Using an IR thermostat, I have found that the boiler flowtemperature is set at around 60degC. Iam guessing that this is because the return temperature is around 54degC. There is only around 5degC drop across therads even with the pump set to its slow speed. Am I right in thinking that the radiators would be more effective with a higher flow temperature?

I’m looking for advice . Is my short-term solution to increase the flow temperature and take ahit on boiler efficiency and my longer-term solution to fit bigger rads, or arethere other solutions?

 

[Scott_D]

Do the radiators get hot?
If the boiler is 2 years old it should be condensing

 

[joni os]

Increasing temp of rads will increase output. Difference between room temp and rad temp known as Delta T. At the moment your Delta T is approx 40. Increasing flow temp by 10 degrees to get Delta 50 will increase radiator output by 25%. You will also experience a greater difference in flow and return across rads.

 

[IanMK13]

Sorry - My mistake. I should have read what I had written more carefully. Of course, it's a CONDENSING boiler.
Yes, the radiators are hot. Approximately 60degC in and 55degC out.

 

[IanMK13]

Thanks Joni OS. I'd read that a 70degC flow was more likely the temperature I should have at the boiler and understood that the rad outputs were specified at this temperature but didn't know that the rad flow-return temperature differential would be different with a higher flow temperature.

 

[PhoenixServices]

Once you have upped the temperature, I would suggest giving the system a balance. There is a thread for it but I don't have the link currently.