- Messages
- 19
ok, so I have a underfloor heating manifold with 11 ports (see pic)
Rooms struggle to warm up. Think I know why, here's what I've tested:
1. Pressure expansion tank in garage 2 bar - ok
2. Boiler working, water hot - ok
3. Thermostats calling for heat and actuators respond - ok
4. Flow: all meters were totally corroded, had to bin and put new ones (see pic)
5. New flow meters show minimal flow (0.5 - 1 lt pm)
6. Checked valves, opened all fully, no stuck pins - no change to flow
7. Flushed system with garden hose, line by line, no air locks
So, it seemed flow was the problem. To test this I closed the return valve and all actuators, and opened the drain valve on the pipe directly from the pump (I.e. flow side)This showed me the pump was delivering 7lt pm, and the water was piping hot (steam off the bucket).
To check the rate the water was going through the underfloor heating pipes, I closed the drain valve on the flow side, and opened one actuator and opened the drain valve on the return side, and closed the return valve, so water would only flow through the underfloor pipe and then through the drain. This showed 7lts pm was flowing through, so same as the flow side, I.e. No blockage.
THE ANSWER?
Is the problem just that the system is only getting 7lts pm? I'm thinking that at an average of 1.5 lts pm, per port/line, it might need a total input flow rate from the pump of around 15-20 lts per minute? If this is correct, is the pump the problem?
PUMPS
there's a pump directly on the manifold (standard Grundfos - see picture), and there's a pump in the garage (looks higher tech - see pic), and not sure how these may support each other?
I'm wondering if the corrosion on the flow meters might suggest other components could be corroded and not working properly. The pump sound normal. I have unscrewed the valve and no air in it.
CAN YOU DIAGNOSE THE PROBLEM??
Mike