Balancing system

[thenuke10]

Hi

After some advice on balancing WB highflow 440CDI condensing boiler system feeding approx 12 rads. My understanding is to get the boiler working at max efficiency return flow temp should be <50 Deg C. I also understand the principle of adjusting lockshields. What I am after is some help. Is the flow temp required approx 70 - 75 deg C To get the 20 deg C temp drop across the rads. Is the flow and return temps taken at the boiler. Also the pump is set to 3 (max) and the literature for the boiler says this is what it should be left at. If I can,t get the 20 deg drop by adjustment is it ok to adjust this.

regards

 

[D_Hailsham]

My understanding is to get the boiler working at max efficiency return flow temp should be <50 Deg C.

Less than 55°C is normally considered good enough.

Is the flow temp required approx 70 - 75 deg C To get the 20 deg C temp drop across the rads.

Yes, you set the flow temperature with the control on the front of the boiler. A 20°C differential is not important for efficiency; it's the return temperature. So you can run with a lower differential, provided the return is below 55°C.

Is the flow and return temps taken at the boiler.

Yes, and across each rad. The idea is to get them all the same.

Also the pump is set to 3 (max) and the literature for the boiler says this is what it should be left at. If I can't get the 20 deg drop by adjustment is it ok to adjust this.

If the mfr says leave on 3, then I would leave it there.

One thing to note is that rad outputs are measured with an 11°C differential. They will give out about 15% less heat if they have a 20°C differential.

You can find the balancing procedure Here

 

[bengasman]

You will need a fairly decent contact thermometer for that.

 

[thenuke10]

Many thanks guys, will be firing up the CH soon, cold blooded wife starting to feel the cold. I'm still walking round in shorts and t-shirt. got a Infrared Thermometer, I take it this is ok

 

[bengasman]

... got a Infrared Thermometer, I take it this is ok

It is a start, but unsuitable to measure flow and return on the boiler

 

[D_Hailsham]

... got a Infrared Thermometer, I take it this is ok

It is a start, but unsuitable to measure flow and return on the boiler

Mine works OK for measuring boiler temps.

You just have to think of the IR as a torch with a conical beam. The further the way you are from the object being measured, the larger the area over which it averages the temperature. If you hold the IR right against a pipe, you will just measure the temperature of the pipe.

All IR's quote a "distance to spot size ratio"; e.g 8:1 means that at 8 cm distance the measuring area will be 1 cm diameter.