What happens if I get water in my gas boiler flue?

20 October 2022

Getting water in your gas boiler flue can be a big issue for your hot water and heating system. In this blog post, we discuss how water can get into the flue, the consequences, and what you can do about it.

How does water get in a boiler flue?

There are many reasons why you might get water in gas boiler flues. One common reason is that condensation from the cold air outside has seeped into your chimney (or flue) pipes.

This is typically because there is insufficient insulation around your chimney or because rainwater has found its way inside via an open-air vent or poorly sealed joints between sections of pipe.

Other causes include a leaky chimney cap or poor design of the chimney stack which allows for rainwater to enter through cracks and then trickle down into the gas boiler flue pipes below.

Impact of water getting into the flue

If you get water in your gas boiler flue, it can lead to a number of different problems and one of the most common is that the water will freeze and block off the flue, which could cause your boiler to overheat and possibly explode.

If this happens, it could be dangerous for anyone near it when it explodes. If you are aware of any water in the flue, call Profix immediately and one of our gas engineers will visit you to undertake any necessary boiler repairs.

If considerable damage occurs, it may be necessary to buy a new boiler as your existing boiler might not be repairable. See boiler brands for more information on boiler brands for sale and installation by Profix.

In the warmer months, if the water is not removed quickly, rather than freezing, it can lead to a build-up of steam pressure. This can cause the pressure valve to open and release excess steam. If this happens, it will be a good idea to have the gas boiler serviced as soon as possible to avoid any need for boiler repairs.

Rain water coming into Ideal Combi boiler through the flue

If you have an Ideal Combi boiler and are concerned about water getting into the flue, then we can help using our experience with installation, servicing and boiler repairs. We provide support, including repairs and installation of Ideal Combi boilers.

The water could have entered from having a broken seal or from having a flue that’s too steep and this may need to be corrected as well.

Can water cause Ideal Combi boiler main circuit board to blow? 

Yes, it can. If water from the flue gets inside the boiler then this can create a build-up of moisture, causing damage to the electrical components, causing them to burn out.

If this happens then a new boiler might be required as the PCB (the main circuit board) is a core part of the boiler.

Getting water inside your boiler should be avoided, and this can be done with regular gas boiler servicing. If you are concerned that water is in the flue (or it may have entered the boiler), call a gas engineer immediately to assess the situation. If damage is done, they can then assess if boiler repairs are needed, or if a new boiler is required.

For gas boiler servicing, we recommend having your boiler inspected every year.

All our gas boiler servicing is carried out by our registered gas safe engineers.

Have concerns about your boiler?

If you have any concerns about your boiler not working properly, call us today. When it comes to having professional, experienced gas engineers, York and the surrounding area is covered by our best-in-class support. Call our gas engineers in York today.