The church heating is not working today (groan) and it appears that the pump is not circulating the water. On trying to take the cover off the pump spindle (to check it is free) water spurts out (and it was hot because the boilers were working!). It is a pressurised system, but is it normal for water to come out of the pump spindle?
Central Heating Pump
Feb 18, 2007
27 Replies
Yes, it's used to bleed air out of the pump in some cases. Doesn't usually come out very fast. The water also forms the rotor bearing in most designs.
A good clue for pump not working is that the pump body is hot, but the pipework isn't. Note that pump might not be working even if the rotor is spinning -- sometimes all the impeller blades wear away.
In article , Andrew Gabriel writes
The water spurts out pretty fast!
The pump sounds like it may be working but most of the pipework is cold except those parts where convection could be providing some heat.
Time for the engineer! :-(
Nice for the church to get a reply from A Gabriel...
Might it be that the pump rotor has seized? I'd switch off pump & boiler, shut isolating valves before & after the pump. Remove cap at the middle of the pump and spin the rotor with a small screwdriver. Ensure it revolves freely. They are usually canned rotor/glandless pumps and the clearance between can & rotor is small, so they often get stuck by small bits of debris. Spinning it will often free it up.
Open valves, pump power on, check rotor is spinning, replace cap, boiler power on.
Minor problem is that there are no valves either side of the pump! However, I might go down this afternoon and see whether I can isolate a small enough part of the system to allow me to release the pressure...
I noticed our radiators were not getting as hot downstairs as they used to. The pump was running and was set on the minimum speed of 3 settings. I turned the pump up to max and left it running for 5 minutes before resetting to it's original setting after which the radiators heated OK.
I think they really wanted a miricle...
On Sun, 18 Feb 2007 13:25:19 +0000, John mused:
Just spin the pump then. I've not isolated one yet before taking the centre cap out and spinning it.
Don't you do those on Sundays? ;-)
Are you sure? The valves are usually built into the flanges that connect the pump into the pipe work. Somewhere on each brass flange there should be what looks like a small slotted screw. This is shaft of the ball valve in each flange. Turn each 90 degrees using a screw driver to isolate the pump.
On Sun, 18 Feb 2007 14:11:13 +0000, Steve Firth mused:
You can get pump flanges with no valves built in, uncommon, but not unheard of.
In article , Lurch writes
This is a large pump which goes onto about 40mm pipe with bolted glands
- I couldn't see a valve.
Yes, I realise, hence "are you sure?"
On Sun, 18 Feb 2007 20:39:54 +0000, Steve Firth mused:
Just clarifying. ;)
On Sun, 18 Feb 2007 16:21:33 +0000 someone who may be John wrote this:-
Then get some fitted. Saves time and water treatment chemicals when the pump is replaced (which is generally more frequently than the pipework).
On 40mm threaded steel pipework?!
Copper actually - but yes it would be a good idea to get some valves fitted!
Did the engineer visit?
How about the angel Gabriel?
The engineer has yet to descend with his harp and angel wings - I will let you know the outcome!
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