megaflow pressure drop after new PRV fitted

[bolst3r]

Noticed the main PRV leaking last week so called heatrae and they verified the serial/install confirmed it was under warranty and sent out an engineer to replace the faulty part. Can't fault the service but since it's been replaced the water pressure it good for 30 seconds then drops off. I've recharged the system (about to try again) but not sure what else I can do.

Any suggestions?

 

[bolst3r]

On a side note i've also noticed the temperature mix has changed since the PRV has been changed. We now need to mix less cold water in to get the show hot which would suggest the flow of cold water has now been reduced.

 

[Dan Robinson]

Perhaps the new PRV has a difference pressure rating (don't like Megaflos so can't tell you what it was or is - probably 3.5Bar).

Temperature mix is probably a figment of your imagination/seasonal change in water temperature outside/the engineer turned down the cylinder stat when carrying out the work/all of the above.

 

[bolst3r]

Temperature change is defiantly not a figment of my imagination as both myself and wife noticed it and it's a considerable change. The engineer didn't touch anything on the cylinder when the PRV was changed as it's a pig to get to.

I have just noticed that the pressure/flow from the hot water tap is now double that of the cold. Based on this finding it explains the pressure drop. If the cold flowed as before then I would need more hot water to balance the temperature therefore the shower would be chucking out twice the amount of water so for some reason the new PRV is limiting the amount of cold water going through the system.