Is it possible to to measure water temp in cylinder by measuring return pipe to boiler?

[fdiddy]

Hi All,
Trying to find an accurate way of measuring the temp of the water in a hot water cylinder, i have a temperature probe which is currently attached to the boiler return at the bottom of the cylinder. is that an accurate way of measuring the water temp in the tank?

I know that as a last resort i can remove some insulation a 1/3 of the way up the cylinder, and attach the sensor but obviously would like to avoid that for obvious reasons.

thanks !

 

[ericmark]

I would not think so, my boiler was set to run for 30 minutes 4 times a week, and it would run 20 minutes approx before the boil cuts out, so clearly hot water returning to boiler, but the water out of taps is only warm it's not really hot.

Now I have solar panels, so use an immersion heater to heat the water, using excess solar, but it is not long enough so only heats up top 9 inches.

 

[Madrab]

Hi All,
Trying to find an accurate way of measuring the temp of the water in a hot water cylinder, i have a temperature probe which is currently attached to the boiler return at the bottom of the cylinder. is that an accurate way of measuring the water temp in the tank?

I know that as a last resort i can remove some insulation a 1/3 of the way up the cylinder, and attach the sensor but obviously would like to avoid that for obvious reasons.

thanks !

Nope, system water temp would not be a good indicator.

It also depends on what temp you want, 1/3rd of the way up on the cistern allows the stat to control the mean HW temp in the cylinder but obviously it's not hyper accurate as it will always be hotter at the top than at the bottom with layers in between and any sensor would only be able to tell you what the temp is at the sensor point.

To get a more accurate average temp it would need 2 sensors, one at the top 3rd, one at the bottom 3rd and then some clever logic to average out the temps and output to a display.