Manifold temperature issue

[swisscheese]

Looking for collective wisdom on why one of our manifolds will not heat to the same temp as another. 

 

It is usually around 5 deg C lower than the discharge temp.  I have continually tried balancing the flow but I cannot seem to get it to get any closer to the discharge temp.

 

Any check list or Any ideas greatfully received.

[Nickfromwales]

Input or output temp ?

[swisscheese]

Sorry  - Yep, input - for example if the ASHP is knocking out a discharge temp of say 40degC, the manifold temperature gauge in the input pipe to the manifold will report 35degC

 

The other Manifold "T'd" off will be around 40degC.

Thanks

 

 

 

[AliMcLeod]

1 hour ago, swisscheese said:

for example if the ASHP is knocking out a discharge temp of say 40degC, the manifold temperature gauge in the input pipe to the manifold will report 35degC

 

Have you considered a dodgy gauge? Measure the temperature with an external thermometer probe/laser?

Edited January 21, 2019 by AliMcLeod

[swisscheese]

1 minute ago, AliMcLeod said:

 

Have you considered a dodgy gauge? Measure the temperate with an external thermometer probe/laser?

 

Thanks, Good point - I have, I swapped over the guages from one to the other.

 

By touch  - it just feels cooler.

 

[AliMcLeod]

13 minutes ago, swisscheese said:

Thanks, Good point - I have, I swapped over the guages from one to the other.

 

Ah, ok, I'll leave it to the experts then

 

A schematic may help. eg, if the hotter manifold is tee'd off "before" the cooler one, could there be some "backwash" from the now-circulated (and therefore cooler) water reaching the second manifold?