Pump Speed Settings

[dazzlerpalmer]

I have a celsia multi-head Myson single pump on a four bed house connect to a Potterton Supima 60F boiler. Three port valve. There are 12 radiators (some large doubles)

When I turn of the system all is ok except some rads don't seem to get enough juice (I have balanced the rads as best as I can). The pump speed is set to 1. If I set the pump speed to 2 or 3 the expansion pipe starts spitting like a cobra.

I suspect there is a sludge build up. How can I sort this out easily without a power flush? Any ideas as to what is causing this problem.

And is this boiler/pump powerful enough? I have worked out the rads in the house are approx 62,000 BTU and the boiler has a max of 60,000 BTU.

Cheers

 

[ChrisR]

Pump speed 1 will not get the energy out of the boiler, it will need at least 2, or maybe 3 depending on the pipe sizes.

Expansion pipe? If you mean the Vent, if the system is "pumping over" it's a sign that the plumbing isn't designed properly. Occasionally sludge interferes with the water flow to cause it.

Running with a system cleaner then emptying may help a bit but nowhere near as much as flushing forcefully. You can do that with the mains, or better with powerflusher (can hire) and the right chemicals.

 

[namsag]

Celsia multihead pump is basically two pump windings built into one head speeds 1/ 2 are equivalent of speeds 2 /3 on a 15/50 pump and speed 3 is euivalant of of a 15/60 pump speed 3 if i remember right. so on a normal system speeds 1or 2 should be sufficent and speed 3 only selected for combi`s and larger systems. does sound if you have a partial blockage though

 

[bathjobby]

'Pumping over' into F/E tank is most commonly caused by F/E tank level being too high. Whatever the level is in that tank is also the level in the expansion pipe, if its high, very little activity is required to make it flow into tank. The F/E tank level should be just enough to cover the feed pipe at the bottom of the tank, usually just a few inches / cm's. The Expansion pipe should also reach a height of around 3' / 1 mtr above the F/E as this further increases the activity required for pumping over to occur.