Upgrading System

[Sustech]

With the boiler running I have a flow temp out of 84 degrees and a return of 71. (unfortunately using an infrared thermometer)

The flow is coming out the top of the heat exchanger.

Can anything be determined from this?

[Agile]

The design temp is 82°C for the flow and 71°C for the return.

With that the rads should keep the house at 21°C when its -1°C outside.

You really need a contact thermometer to measure the temperatures accurately.

Either you wife is cold skinned or your rads are rather undersized.

Anything you can do to improve the insulation will be very cost effective.

Hows your 450 mm of loft insulation?

Tony

[Sustech]

Think you have possibly got a point.
The living room is mainly an extension with a flat roof. I don't know what amount of insulation was installed when the extension was built. (done before I bought the house)
Using various sizing calculators I should need around 11700 btu/h. I have two 500 x 900 double panel compact rads which add up to 1000. May need to make one of them bigger.
Insulation in loft is already quite good, but I am going to replace it all eventually as I re-floor it.

[Agile]

Well in that case your living room is seriously under heated.

Its easy enough to check what the insulation is in the flat roof with a small hole.

Use your IR thermometer to see what the wall and ceiling temperatures are.

If the ceiling is less than a degree or two below the room temperature then you need more insulation.

Tony

[Sustech]

Thanks,

I will probably change one of the radiators over the christmas period.

I have come across another little possible anomoly.

I am using a smartfit system, Y plan, 24 hour unit. The room stat function is switched off and the hot water set to 60 degrees.
The hot water cannot make its mind up as to what temperature to heat to. One morning it could be 60 degrees, the next morning 75.
When the one of us has a bath in the evening, the hot water struggles to reheat.
So, today, I set the hot water to priority. I have just come back home and found the radiators cold and the hot water at 80 degrees. Just as I looked into the loft, the valve changed over to rads.

Have I got a valve problem, or is it the unit? As the info shows the hot water temperature I am assuming the tank stat is working ok. Just can't see why the temperature should be allowed to go over 60 degrees.

[Agile]

I cannot guess where the problem lies but I would first be making an electrical check of the control signals to the valve to see if the electronics are giving it the correct instructions.

Tony