On 27 Jan 2006 02:12:38 -0800, in uk.d-i-y "new to diy"
wrote:

Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)? Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

Any advice greatly received as always.

1 Read the balancing FAQ if you haven't already
http://www.diyfaq.org.uk/plumbing/rad-balance.html

2 Apply a black tape patch as suggested by others and take readings off
that. Ignore the laser spot and put the IR thermometer sensor close to
the black tape, say 2 or 3 inches away. Wave the thermometer around a
little and look for a maximum reading, which will be when it is truly
pointing at the black patch.

3 As the rad warms up, the flow end gets hot first.

4 Your figures of 16 to 27 make no sense. A hot radiator should be well
over 50 degrees Celsius, possibly up to almost 80C.

Phil
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