Biasi 24S boiler...only tepid D H W flow?

[Agile]

The blue tap test has demonstrated that the obvious cause of a 10° temperature difference between the boiler and hot tap is not a cross coupling.

I am not convinced that your measurements have been meaningful.

Could you do the following test EXACTLY as I have listed it then I can tell you the probable cause.

Set the boiler to DHW only.

Set the shower to hot only and the flow rate to 8 li/min and then measure the temperature at boiler out pipe and then at shower output after its stabilised for a few minutes.

I would remind you I was basing my suggestion on the information that there was a 10°C loss between boiler and bathroom. I am now begining to wonder if this was true.

Tony

 

[Hunkamunka]

Hi again Gasguru...had to go out yesterday PM and am at work today...is there a setting on a boiler to give flow rates (cant see how) or do I just set up on a bathroom tap using a measured container as you have previously suggested....I will get around to this test asap...probably a few days as I work late.

 

[Hunkamunka]

Hi again Tony...out yesterday PM but thanks for your message......the 10 degree difference you mention was my fault as I did not take into account rates of flow..(see suggestion by Gasguru ).....will be carrying out testing again as soon as I get a day when I am home early enough we are up to our necks at work at the mo...Gasguru has asked me to do a test using a specific flow rate too...is there an easy way to set this on the boiler or do I just use a measured vessel at the tap?

 

[Agile]

He and I are not independently asking different things, its the basic performance test, and it needs to be run without disturbance for afout 5-6 minutes to stabilise the temperature.

You set the flow rate at the tap but do this when nothing else in the house is taking water, no washing machine! Measure with a jug or better a larger bucket or saucepan.

Tony

 

[ChrisR]

if it is a real pain to get out

Doddle.
Drain, a nut or two to undo, then 2 allen screws (one needs a long ball ended one)