the problem is called kettling: With regards to kettling, banging or popping noises in the central heating boiler, this is usually caused by either lime scale and corrosion debris becoming baked onto the inside surfaces of the heat exchanger, leading to localised boiling (due to hot-spots).

This is a common problem with low-water content wall-mounted boilers over about 10 years old. Provided that the heat exchanger is not too scaled up, or damaged, then by following the procedure below, may restore it back to normal, for a few years more.

A good method to clean the boiler and system to prevent a reoccurrence of the noise problem is to use Fernox Heavy duty Restorer and Fernox DS-40 boiler descaler as outlined by Fernox, so avoiding boiler replacement and re-plumbing. Note that FERNOX DS-3 SHOULD NOT BE USED, THAT IS FOR WATER HEATERS. ONLY DS-40 OR SIMILAR PRODUCTS SPECIFICALLY FORMULATED FOR CENTRAL HEATING SYSTEMS SHOULD BE USED.

Hello, noise, banging and clanging often means that the heat exchanger is scaled up and or the pump is worn out. The noise is called kettling and is caused by the building of scale on the heat excahanger causing oxygen bubbles to be formed on its surface, just like the noise you get from a scaled up kettle or immersion heater. You can buy boiler noise silencer and pour into the header tank, check the label, as most of these can stay in the system, this stuff breaks down the scale. But really you would need to drain some water off the system first, not something you should do if not competant or if it is the landlords resposibility. I would compalin to the landlord. The system needs to be power flushed and de-scaled. Bear in mind that a scaled up boiler is very inefficient as is sludged up radiators. A slow pump can also cause kettling as the water isn't moving through the boiler fast enough and it can boil, hence steam and then banging. A gas safety test will only state the gas supply condition and flue/vent tests, it will not cover the wet side of the boiler.
The Potterton Flamingo has a permanent pilot and was <65% efficient when new 20 + years ago, with problems above I would estimated <45% efficient now, more of the heat is going out the flue than to the house!!

it sounds like air but you best ask your landlord when it last had a gas safty checked it should by law be every year Thomas

Hi there,the boiler may be old,but the problem could be more to do with the pump/system/pipework.sound like it needs to be checked out properly by a trained engineer...Brian

In my opinion I would say that you probably have air in the system but there may also be a bit of a blockage.A powerflush may cure it but to be honest a boiler that age I think would be more economical to replace.
Tony