Rad Balancing Experts Looks In Please

[IA76]

Hi All

My mate has one of those laser digital temp readers so I borrowed it to test how well my CH is balanced.

All my rads do get hot but i just though I would see if there was room for improvement.

temps measured at pipe going to trv & pipe going to lockshield in degrees

These were the results:-

room=living - trv temp=21 l/s temp=23
room=kitchen - trv temp=23 l/s temp=26
room=utility - trv temp=22 l/s temp=21
room=dbath - trv temp=15 l/s temp=13
room=front - trv temp=16 l/s temp=23
room=dhall - trv temp=23 l/s temp=21
room=bed1 - trv temp=22 l/s temp=28
room=bed2 - trv temp=26 l/s temp=24
room=bed3 - trv temp=12 l/s temp=13
room=ubath - trv temp=41 l/s temp=33
room=uhall - trv temp=24 l/s temp=23

Any suggestions for improvements?

Thanks in advance

p.s I read that the difference between pipes should be 10-12 degrees??

 

[Softus]

These readings look ludicrously low, but if you're happy with the heat output from the rads, then take no further action. Oh, except for handing back the thermometer.

If you're not happy, then consider turning down the pump speed, or partly closing all of the lockshield valves, or turning up the boiler temperature, or any permutation of the above.

Have you ever the old adage: "If it ain't broke, don't fix it."

 

[ChrisR]

Glad I don't sleep in bed 3.

 

[ArtfulBodger]

Laser temperature guages will only work on non reflective surfaces. If you want to measure the temp of copper, chrome etc you must put a bit of masking tape or similar on it.

If you want to check the machine, point it at the palm of your hand, you should get a reading of 29-31 degrees.

 

[chrishutt]

Laser temperature gauges will only work on non reflective surfaces.

I thought they were infra-red, the addition of a laser being just for aiming purposes.

Anyway, Artful's point is right, hence your very low readings. I think it might help if surface is flat too - anyone know?. You may get better readings off the radiator itself - say at the top flow end for flow temp and bottom return end for return temp.

Your flow temperatures should get up to 80C with the boiler on highest setting. It's also increasingly common to have a 20C drop across rads, which is better for condensing boilers especially because the lower return temp will encourage condensing.

The only disadvantage of a 20C temp drop is that the average temp of rad is then about 5C lower than at 11C drop, which would reduce heat output to room by about 10% - not normally critical.

consider turning down the pump speed

Not on a combi boiler - on no account should pump speed be altered on combis.

 

[Softus]

consider turning down the pump speed

Not on a combi boiler - on no account should pump speed be altered on combis.

Quite right - apologies - must be more careful late at night

 

[slippyr4]

consider turning down the pump speed

Not on a combi boiler - on no account should pump speed be altered on combis.

That's interesting, why not?



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To the OP - did you take the TRV heads off and then let the rad settle for a while before you took the temperature? If the TRV is part closed, you'll get meaningless readings.

 

[IA76]

I'm going to recheck the temps as I think you may be correct about needing to put masking tape on the reflective pipe.

Yes it is a combi boiler and I havn't touched any pump settings (if ther is one!)

After spending a fair bit of time in the rooms with the colder rads last night decorating I now realise thet do need to be hotter.

If I aim for a temp drop of 10-12 across all the rads that's the best way of balancing I think from what I can gather after searchig on here??

The boiler is set to temp 6 (it can go up to 9). At temp 6 it is not hot enough for the TRV's to close when they are set at max.

Thanks for all the info people...much appreciated and some very good tips

 

[chrishutt]

The boiler is set to temp 6 (it can go up to 9). At temp 6 it is not hot enough for the TRV's to close when they are set at max.

Not necessarily so. The TRV head senses the ambient air temperature, which might be warm enough to provoke closing, irrespective of boiler thermostat setting.

 

[slippyr4]

Not necessarily so. The TRV head senses the ambient air temperature, which might be warm enough to provoke closing, irrespective of boiler thermostat setting.

Which is why you should take the head off when balancing.

 

[IA76]

i did it with removing the heads in the end anyway just to make sure readings were correct.

I put a bit of masking tape on the copper pipes and the temp readings are higher than before and more accurate

all rads are now nice and warm

THANKS ALL

 

[olly_k]

Chris is right 'laser' temperature gauges measure the IR energy emitted from an object. I think they also use a normal sensor to give a reference which is why you should let them acclimatise to the room you want to measure in if it is wildly different from anywhere else.
First check your mates meter hasn't got an adjustable emissivity setting, if it has set to .95. As for measuring itself, I find the best readings on pipes are gained by putting a bit of black insulation tape on the pipe in question then taking the measurement.... if the sensor is any good you should see a spot-on reading!