Low hot water flow rate on top floor, 3 storey house?

[LenBeach]

I live in a 6 year old 3 storey house with an Ideal Logic 15 boiler on the bottom floor and a Range Tribune HE cylinder on the middle floor.

Over the past couple of years, the flow rate of hot water on the top floor has degraded to the point that the bath is now a trickle and takes over an hour to fill with both sinks being similar.

I have 2 expansion tanks alongside the cylinder, the hot water tank is showing 3.2 bar, the boiler has just been serviced with no issues.

The plumber servicing the boiler was a little stumped but felt that the Caleffi pressure release valve coming up to the middle floor into the cylinder could be the issue.

The flow rate on the middle floor and ground floor are fine which I assume is due to natural pressure.

Any thoughts on whether the PRV is likely to be at fault?

 

[CBW]

Get your cylinder serviced by a G3 registered engineer. Pressure shouldn’t be that high Imo.

 

[fezster]

There's a strainer in the pressure reducing valve. Have that cleaned as part of your service, it may be partially blocked reducing flow.

 

[Mottie]

Out of interest, what is involved in a G3 cylinder service?

 

[fezster]

This is just what I have observed when having it done:

1. Clean strainer.
2. Check safety valves.
3. Check EV and recharge if necessary. If you have no EV, then the air bubble should be replenished, though IME, not all of them do this by default.