Noisy Central heating Pump

[freestyleal]

Hi there - can anyone help? (Sorry if this is posted in wrong place). We normally run our hot water on constant but I turned the CH and HW off whilst we were on holiday last week. Came back and turned HW to constant again. Also turned the boiler down from 4 to 2.5 (top number is 6) as I wanted to reduce the temperature in the tank to avoid scolding accident (my oldest toddler has just learned to turn on taps). In the middle of the night a horrendous noise started coming from the airing cupboard - I actually thought it was an angle grinder outside! The noise seems to be coming from the pump. I have turned it off completely and am boiling water for baths, washing up etc. Is there a simple solution or am I looking at a big bill? Please help! It's a mega flow system if that helps to know.

 

[foxhole]

New pump, should have isolation valve either side which makes it a simple replacement job and rewire.

 

[conny]

Or possibly air in the system.
Try running hot tap slowly for a short while. (5 mins)

 

[freestyleal]

Thank you for your replies. Turns out that there wasn't enough water in the system as the header tank had run dry because the valve had seized up and the tank was emptied last time we had plumbing problem and the plumber had failed to check that it re-filled and the tiny bit that was remaining had evaporated in this hot weather we have been having. Tank re-filled. Valved freed and lubed and pump now nice and quiet!

 

[conny]

Therefore I was right!