Water pump issues

[marmaduke]

Hi all,

 

I've been having issues with my shurflo 20 psi pressure switch water pump for the last 2 years. Basically the flow seemed to get less and less powerful which meant it wouldn't ignite the gas boiler when turning the hot tap on. It was also very noisy. When I went to investigate it, nothing appeared to be wrong, there was no gunk in any of the pipes. I concluded that it must be a faulty pump, so ordered a new one, this time 30psi.

 

As I went to change out the pump for the new one, there was a bit of faffing around, and for reasons I won't go into, I ended up just trying the "faulty" pump one last time, without trying the new 30psi pump. When I turned it all back on, the pump was not only near silent, but the flow was back to expected and would give me hot water again. I concluded this time that it was the electrical connections that must have vibrated out.

 

However, after a few weeks, the pump returned to it's noisy state again (like a warzone in a cupboard under the sink), and despite me redoing the electrical connections again, it made no difference. The flow appears to be slackening off ever so slightly, but certainly not like the crunch time before. I now no longer have the newer 30 psi pump.

 

I'm at a complete loss as to what is going on with this system. Does anyone have an idea? Cheers,

 

Marmaduke

[OldGoldy]

 

I'm at a complete loss as to what is going on with this system. Does anyone have an idea? Cheers,

 

Marmaduke

 

Yes, check out the content of THIS recent thread

[marmaduke]

I don't think it's to do with having the water cap on too tightly as I've unscrewed it to make it loose, and the same machine gun noise happens. Also, I had checked the feeder pipe and there's no rust there. Still flummoxed.

[DeanS]

Hi:)

 

There are a few things you can check.

 

1. Disconnect the positive wire from the pump.

2. get a bowl.

3. unscrew the outlet pipe from the pump.

4. Balance the pump over the bowl.

5. Let the positive wire re-touch the connection point so the pump starts.

6. Does the pump flow exit the pump fast, and with pressure.

 

If yes, the issue is not with the pump, but a blockage further down the system.

 

Have you checked the input pipe on the gas heater. Some have a filter which gets clogged up.

 

[smileypete]

If you take the pump head apart to investigate, do have a tube of Fernox LS-X handy, Screwfix or similar have it.

 

Smear a sparing amount around the edge of the diaphragm, reassemble and wait as directed. Without the sealer the pump will very likely leak when used again.

 

You could try bypassing the pressure switch temporarily to rule that out, but it sounds very unlikely to be that. But it is good practice to fit a standard 12V auto relay between pressure switch and pump motor to insure the electrical life of the switch.

 

cheers, Pete.

~smpt~

Edited September 27, 2013 by smileypete

[smileypete]

Just had a thought on this

 

The noise and reduced performance could be a failing bearing behind the pump head.

 

Unscrew the three long screws that go into the motor casing, the whole head comes off and there's a standard bearing inside, IIRC it's something like a 6203Z but do check for a number on the bearing, they can be had for just a few pounds online.

 

There's also a die cast insert between the bearing and motor shaft, this can be driven out of the bearing fairly easily using a tube or similar to support the bearing.

 

cheers, Pete.

~smpt~

[George94]

Just had a thought on this

 

The noise and reduced performance could be a failing bearing behind the pump head.

 

Unscrew the three long screws that go into the motor casing, the whole head comes off and there's a standard bearing inside, IIRC it's something like a 6203Z but do check for a number on the bearing, they can be had for just a few pounds online.

 

There's also a die cast insert between the bearing and motor shaft, this can be driven out of the bearing fairly easily using a tube or similar to support the bearing.

 

cheers, Pete.

~smpt~

 

Not bad! On mine it's actually a 6203ZZ.

[OldGoldy]

I don't think it's to do with having the water cap on too tightly as I've unscrewed it to make it loose, and the same machine gun noise happens. Also, I had checked the feeder pipe and there's no rust there. Still flummoxed.

 

In this case I wasn't really referring to the vacuum, but do consider all the other possibilities!