Roaring boiler

[percival]

Boiler type Glow worm 65f. Installed 1989.
Central heating and hot water temperature OK.
Boiler seems to be operating correctly but then gives a very very loud roar then shuts down.
When temperature drops it fires up O/K and the process starts over again.
The other thing I have noticed is the hum from the pump is louder than it use to be.
Are the two problems connected.
Any clues would be appreciated.

 

[shyguy2005]

Does the pump get extremely hot to touch when on?

 

[Rickster123]

Has the boiler been serviced since 1989?...

 

[percival]

Does the pump get extremely hot to touch when on?

Yes it does seem to be very hot

Has the boiler been serviced since 1989?...

No but have used fernox cleaner a number of times

 

[bright spark]

I think ye need to have a gas engineer around t have a look at it.

 

[Dotty]

As above. Not a diy repair.