Over the last few weeks heavy rains have fallen across Ireland and more is expected over the coming days. So, it is useful to know how heavy rains can affect your plumbing and what you can do about it.

Cracked & blocked drainage pipes

Heavy rain makes the ground softer.  Once the earth around the underground pipes softens, the increased pressure placed on the pipes from the heavier mud can then cause shifting. Drainage pipes will also have added pressure thanks to all of the extra rain water flowing through them. These two things combined can cause a crack in your pipes, especially if they are old or already damaged.

Sand and soil then get into the pipe and cause blockage. The wastewater can’t go down the drain, so it flows back up the pipes and comes out at the lowest point — usually it is the shower drain. Another symptom of a blocked drain is when you run water in the bathroom sink, the toilet bubbles and gurgles. The bubbling is due to air trapped in the plumbing system. If this happens, you should call the plumber.

Septic Tank Flooding

If you have a septic tank on your property, the heavy rain may saturate your drain field, meaning that your tank is unable to properly output water.

It can get to the point that your drain water has nowhere to go but back up through the pipes.

All of this can be prevented by limiting your water usage during heavy rain and by having your system checked regularly.

Damage to the Condensing Boiler

When heavy rain puts an added strain on your drainage system, water can run back into the internal pipework in your home. Again, this problem is made worse by leaves and debris in the pipework.

Problems also occur if the condensate pipe is installed incorrectly and it terminates at the rainwater downpipe.  When the downpipe overflows with the heavy rain, it can cause the water to back up the condensate pipe and into the boiler itself.

This causes the boiler to flood and can damage it beyond repair. a condensing boiler that has been flooded with rainwater cannot be repaired, and this type of damage can void a guarantee an installer has with their supplier. 

https://www.phamnews.co.uk/heavy-rain-a-threat-to-condensing-boilers/