Running a boiler can require more maintenance and diligence than other home heating options. Older boilers develop problems that can sometimes be quite complicated.
Even more complicated is that depending on what kind of boiler you're dealing with, a water leak in one heating system could be a serious issue or could be nothing to worry about. Regardless of whether it represents a problem, excess water around the base of your boiler can stem from a number of causes.
1. Pressure Issues
All boilers are fitted with a special pressure outlet pipe. It's a small pipe connection point in the side of your boiler but with no fittings that will occasionally drip water. This allows pressure inside the boiler to escape.
The occasional drips are normal. People sometimes worry that this is actually a leak and cap it off, but for the pressure outlet pipe specifically, that is the worst thing you can do. Your boiler could explode or collapse.
Since occasional drops of water are how the boiler relieves excess pressure, a large amount of water coming out could mean the outlet pipe is working overtime and dripping more frequently. If you find water directly below the boiler on a daily basis, this may suggest that you need to reduce the pressure inside the tank.
Check the pressure gauge on the side of the tank to make sure that this is the problem.
2. Damaged Seals
Another cause of water leaks around the boiler can be damage to the boiler seals. This can allow water to escape through normal use or the boiler pump may even be pushing water out through the broken seals. If this is the case, then it is a good idea to replace both the seals and the pump in order to correct the problem.
Be sure to examine the sides and bottom of the tank to see if water is actually leaking from the seal in order to confirm this issue as your culprit.
3. Cracks in the Body
As your boiler ages, the metal may develop stress fatigues and damage. These will be obvious if they are the source of your water leakage. Repeated warming and cooling will expand and contract the metal piece, and this will eventually lead to a failure such as a crack or split.
A crack in one of these sections is a serious problem, and the repair can be expensive. If your boiler is old, consider replacing it with a completely new one. There's little point in repairing one section of an entire boiler that might need to be scrapped in a year or two.
4. Loose Joints
If you do have to suffer with a large leak around your boiler, it could get a lot worse than loose joints. If that's the case, you're in for a quick fix. Loose joints can often cause a leak around the boiler during hot and cold contraction and expansion, so you should check all the fittings of the boiler and all the pipes and tubes which go into and out of the boiler. While you are checking this, look at the blowdown valve and ensure this is not loose or damaged. This can cause quite a pool of water to build up.
If you still cannot find a cause for your water leak, then you should call your boiler supplier. Arrange for one of their engineers to come and examine your hot water system.