Boilermate 2

[feebeebos]

Hi, A friend has a Boilermate 2 and has now had 3 pumps replaced in the primary circuit in just over a year. the current one is very hot and no hot water is forthcoming. Initial thoughts were the Hot water heat exchanger but then if the primary pump isn't playing the Boilermate wont be getting hot! Any one else come by such a case? My thoughts are blockage, lack of fluid in primaries causing pump to get hot! Thanks in anticipation

 

[ChrisR]

DOn't know the thing at all, but running dry would be pretty bad for the pump! They do normally run quite hot though. It could be dirty water - Wilo pumps are worn out after very few months in sludgy water.

 

[doitall]

Common problem with sludge and pumps

 

[feebeebos]

Thanks for the reply's, what actually wears out in the pumps? Dumb question I know

 

[doitall]

Nothing, they fill up with sludge, and can be taken to bits and cleaned out if you have a couple of hours to spend.

Not cost effective when you're being paid as the labour is more then a new pump

 

[croydoncorgi]

Key point to remember:
CH pumps are WATER LUBRICATED AND WATER COOLED!!!

In other words, water MUST pass through the bearing of the pump ALL THE TIME it's turning. If pump runs dry, you get metal / metal contact, squealing noises and (in a few minutes) a knackered pump.

And if the water is dirty (especially full of black sludge which is actually a very fine oxide powder) the dirt will get into the bearing and wear it out very quickly - within months is common.