Boiler noise

[eddy42]

I have a problem with an Ideal Standard cast iron boiler 50,000 btu, I am getting a slight noise from the inside of it. System is 7 years old, Flowmax hot water store, 2 pumps and mains pressure hot water. Recently I drained the system and changed a radiator to a small towel rail "Mere" supply pipes changed to 15mm from 10mm, have turned the rad inlet down to almost off. After filling the system and adding 2 lt of Sentinel also bleeding the rads I am getting a slight noise from the boiler from a distance its like someone bouncing a ball against a wall every now and then, putting my ear to the boiler its from inside the boiler not the hot water tank. The boiler is in a utility room wall mounted, feed pipe go up into the ceiling and across into the garage and into the airing cupboard, pump are set on high or '3' the hot water store is 120 lt tank no water or pipes in loft

I have two raised pipes with screw caps on them by the hot water tank have opened these to let the air out. How can I tell which is the first and last radiator in the system.

Also on the cold water supply to the tank there is a small blue tank with a screwable cap on it, i say keep to 2 bar pressure. I've never filled this with air in 7 years what is this for and what does it do? we live in fairy hard water area




Many thanks

 

[oilman]

For the boiler noise, use an on-line boiler silencing chemical (or was that what you used?).

Also on the cold water supply to the tank there is a small blue tank with a screwable cap on it, i say keep to 2 bar pressure. I've never filled this with air in 7 years what is this for and what does it do? we live in fairy hard water area

The blue tank is an expansion vessel. This should be checked anually at boiler service time would be a good idea. If you haven't got a manual for the cylinder, ring the manufacturer. It may be something they class as a user operation, otherwise you should get a service engineer to do it, BUT HE MUST BE CERTIFIED TO WORK ON UNVENTED CYLINDERS. This is more legal than gas!! Unvented cylinders are a bomb waiting to go off, and need treating with respect. Failing to look after the blue tank will result in the need for replacement (and you CANNOT do it). It will also mean the expansion relief valve will allow water to drip out, and that will eventually mean you need one of those too.

 

[eddy42]

I have a manual for the flowmax but it doesn't mention what to do with the expansion vessel. This system was installed by the builder 7 years ago

I have had the boiler serviced twice in 7 years both times the Ideal engineer never touched the tank of Blue expansion vessel or even looked at the copper tank.

I have had a closer look at this expansion vessel it looks like the figure of 10 bar is stamped on it and no as I thought 2 bar

Would any pressure build up escape through the pipe leading to the header tank which is above the hot water tank.

What do you recommend get someone to look at it after 7 years make sure its safe?


As for the boiler I have put 2 Lt of x100 sentinel in the system but nothing else

 

[eddy42]

You mention about an expansion relief valve whats it look like and
where will it be?

I can see a hot water mixer / blender valve but thats all.

The tank is made by IMI range FM4651

I have seen other houses in the street using the same system getting steam coming out of the header tank over flow which is on the side of the house.


You have me a little worried now !