Help Meter and pump flow rates

[Matt]

Having a play with workshop heater, and realise we may have a problem and need some help

Is this right that the pump says it's pushing 3.4m3/h the meter says it's only having under half that back through.

Is it the pump or the meter that needs calibrating or meter that's wrong.

 

[Doing it for the kids]

I would agree, what size pipe?

3.4 m3 doesn't sound like much but the Grundfos pumps are pretty good

 

[f0ster]

3.4m3 is 3.4 cubic meters an hour, where is the meter/pump located. does the boiler have a back end mixer on it, if it does is the mixer before the bypass/mixer.

 

[Matt]

I would agree, what size pipe?

3.4 m3 doesn't sound like much but the Grundfos pumps are pretty good

looks around the 1" 1/2 but will check

 

[Matt]

3.4m3 is 3.4 cubic meters an hour, where is the meter/pump located. does the boiler have a back end mixer on it, if it does is the mixer before the bypass/mixer.

the meter is located on just the flow and return from heaters. cant see anywhere where it could be loosing flow.

i assume the meter shouldnt need setting up otherwise what is the point of a "rhi approved" meter if you have got to set it.

 

[f0ster]

itron and kamstrup heat meters need to have the flow sensor installed in acurate locations. the head has to be horizontal, and it has to be in a straight run of pipe without any joints or elbows near by. post a circuit diagram if you have one.