Veil-McLain boiler making whining noise. Why???

Hi!
I have a problem. My boiler is making whining noise after somebody takes a shower or we do laundry (with hot water). Simply after hot water is running for couple minutes. I figured out, that to the whining noise i need to run hot water for few seconds (it repeats usually 3 times to stop whining completely). I have a Veil-McLain Gold Plus boiler, Veil-McLain Gold CGa Heater and two State Therm-o-Flex space heating expansion tanks in my system.
WHAT IS THE PROBLEM??? WHY IS IT WHINING???

This is an English site mate, though we do have to put up with the odd jocks, welsh and paddies. (very odd, most of them).
Most people on here will never have heard of the stuff you've got installed. Best try and find an american site.

sooey said:

This is an English site mate, though we do have to put up with the odd jocks, welsh and paddies. (very odd, most of them).

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Kevplumb's in Tennessee isn't he? Surely he could just nip up to New England with his tools. It's not far. Where is he when you need him?

Better to go in the fall though.

Try Heating Help. They are USA based.