- Most common
- Ticking while heating up or cooling down
- Usually harmless
- Ticking, a short gurgle after bleeding
- Get it checked
- Banging, rumbling, repeated clicking
- Service
- €145 incl. BTW plus materials
Ticking while it heats up or cools down
This is the sound I’m asked about most, and on an Intergas it’s normal. The aluminium front plate over the burner is bolted onto the heat exchanger. As the boiler heats up and cools down, the metal expands and shrinks, and it ticks where the surfaces meet.
It doesn’t damage anything, but it can be annoying, especially if the boiler hangs near a bedroom. Intergas supplies a ceramic grease for it. On older models it goes on the fixing points, on newer ones on the front plate itself. I carry it and apply it during a boiler service. You can see how that looked on a recent job in Zaandam.
Other makes can tick a little as they warm up too. A few ticks that stop once the boiler is warm are nothing to worry about.
Gurgling or bubbling
A gurgle in the boiler or the radiators usually means there’s air in the system. Bleed the radiators, then check the pressure, because bleeding lets some water out. My guides to a radiator that won’t heat up and boiler pressure walk you through both.
If the gurgling comes back within a few weeks, air is getting in somewhere or the pressure keeps dropping. That’s worth having looked at.
Banging, rumbling or a kettle sound
A rumble like a kettle coming to the boil, or a bang when the burner fires, usually means water isn’t flowing through the heat exchanger as it should. Sludge in the system, a pump that’s struggling or deposits in the heat exchanger can all cause it.
This one isn’t a DIY fix. It makes the boiler work harder and it tends to get worse, so have it checked. A service with a clean of the heat exchanger often solves it.
Whistling or a high-pitched sound
A whistle can come from low pressure, air in the system or a valve that’s partly closed. Check the pressure gauge first. If the pressure is fine and the whistle stays, it needs an engineer.
Humming or buzzing
A steady hum is usually the pump or the fan doing their job. It only needs attention when it gets louder over time, starts rattling, or comes with other problems such as radiators that stay cold.
Clicking that doesn’t end in a flame
If you hear repeated clicking and the boiler doesn’t fire, it’s trying to ignite and failing. Most boilers stop after a few attempts and show a fault code. That’s a repair, not a noise problem. See boiler repair for what to send me.
When a noise is an emergency
If you smell gas, leave the property and call 0800 9009 from outside. If a CO alarm goes off or you suspect carbon monoxide poisoning, get everyone outside and call 112. Don’t wait to work out which noise it is.
Getting it looked at
Send me a message on WhatsApp with a short video of the sound, the make and model of your boiler and your postcode. A boiler service is €145 incl. BTW plus materials, and I’ll tell you before the visit if I think it’s more than a service.
Common questions
The front plate is bolted to the heat exchanger. As the metal heats up and cools down it expands and shrinks, and that ticks. It's harmless. Intergas supplies a ceramic grease that stops it, which I apply during a service.
Usually not, but a boiler that bangs, rumbles or keeps trying to ignite should be checked. If you smell gas or a CO alarm goes off, that is an emergency, not a noise problem.
No. The fix means taking the casing and the front plate off a gas appliance, which is work for an engineer.
Record a short video on your phone while the boiler heats up and send it on WhatsApp with the make and model. A sound is much easier to judge than to describe.
