is there a pin sized hole in my boiler?

rich1000

hi if anyone can help please?

the water pipes make a loud noise first thing in the morning when i turn the hot water tap on... the downstairs neighbour suggested there could be a pin sized hole in my boiler..

is this expensive to fix? just as its approaching xmas i might have to get this repair work done later on then..

moneysavingplumber

This sounds more like simple 'water-hammer' to me. More info on your system would help. If it's open-vented then the ball valve in your cold water storage tank may be causing the noise via vibration caused by it's closing action, hence it making the noise when you run the hot tap.

If you're in a flat then it's likely you have a 'combination CYLINDER' (also known as a 'fortic' and not to be confused with a combination boiler, see below). The coldwater to fill the cylinder is stored directly above it in another compartment of the cylinder which is filled via a ball-valve. If that's the case then my explanation above is all the more likely.

If you have a combination BOILER then it could be caused by 'o' rings or a sticking diaphragm in the divertor valve, or a blockage in the plate heat exchanger if applicable.

Pinholes in boilers and cylinders tend to cause visible leaking.

rich1000

hi moneysavingplumber i do stay in a flat and each flat only is only run on electric electric - not gas.

My boiler is a Heatrae Sadia - immersion heater - 3kW 240v

im not too sure if thats the information you require... if you need more info then please let me know - thanks

moneysavingplumber

Hi,

Is it an old Heatrae Sadia freestanding white cylinder (between 5 and 6 feet tall roughly) with a flat lid on the top and a ballvalve filling it as you draw from it, or is it a small under or over sink water heater fixed to the wall? Or, is it a Heatrae Megaflo freestanding pressurised cylinder (no lid, just a draw off pipe coming out of the top)?

If it's the first of the three then it's almost certainly 'water-hammer'. Even if it's either of the other two options, it's still likely to be something to do with insufficient allowance for expansion and vibration in the water main.

rich1000

hi sorry for the late reply... i think it's the 2nd one - its attached to the wall..

is this an expensive job if i were to call the plumber out?

thanks again

moneysavingplumber

It depends if it is mounted over or under the sink. If it is mounted under the sink or without an open vented spout or tap, it should definitely have an expansion vessel incorporated into the pipe work somewhere as well as regulated incoming pressure, and a pressure relief valve. The noise could be caused by limescale kettling inside the heater.

rich1000

hi moneysavingplumber.. it's actually the 3rd one.. it's freestanding pressure cyclinder.. im sure now..

i take its an expensive job to sort out?

thanks for your help so far

moneysavingplumber

Sometimes they require an additional expansion vessel between the pressure limiting valve and the cold mains inlet, even though there is an expansion bubble incorporated within the casing. I take it the unit is a direct unit heated off of an immersion heater. If so it may be kettling due to limescale, if that is a problem in your area. If it is an indirect unit that heats via the central heating system then it may be corrosion or a pump problem.