A tundish is a small but important device that is fitted close to a boiler’s pressure release valve. Its main purpose is to allow homeowners and heating engineers to easily detect if water has escaped from the system due to high pressure levels. In this article, we will discuss the functions and benefits of a tundish, and why it is essential to have one installed in your unvented hot water system.
What is a Tundish?
A tundish is a safety device that acts as a barrier between an overflow pipe and a drain pipe. It is a small funnel-shaped component that is connected to the overflow pipe, which is in turn connected to the pressure release valve of the boiler. The tundish provides an air gap through which someone can see if water is flowing from the pressure release valve, and it prevents unsanitary water from the drain pipe from entering the system.
What does a Tundish do?
A tundish has two main functions. Firstly, it provides a visible indication of whether water is flowing from the pressure release valve. If water is dripping from the tundish, this is a clear sign that there is a problem with the system and that a qualified heating engineer should be called to inspect it.
Secondly, a tundish is an important safety feature that prevents unsanitary water from entering the system. If there is no tundish installed, water from the drain pipe could potentially contaminate the hot water supply, which could pose a serious health risk to the occupants of the building.
Should a Tundish Drip?
If water is dripping from the tundish, this is a clear sign that there is a problem with the system. It could indicate that there is a fault with the pressure release valve, or that water pressure in the system is rising too high. In either case, a qualified heating engineer should be called immediately to inspect the system and resolve the problem.
Do I Need to be Qualified to Install a Tundish?
It is illegal to make adjustments to a boiler system without proper training, as determined by the Local Authority Building Control. Therefore, you should not attempt to install a tundish yourself unless you are a qualified heating engineer. The tundish must meet strict regulations, such as being placed at least 500mm from the pressure release valve in a visible position, and having the correct size of discharge and external pipes.
In accordance with the UK government’s G3 Building Regulations for unvented hot water systems, the discharge pipe from the pressure release valve should be 15mm and the pipe carrying the water outside the property should be 22mm. Additionally, the discharge pipe from the tundish must be vertical and made of metal or other materials that can withstand hot temperatures.
In summary, a tundish is an essential safety device that prevents unsanitary water from contaminating the hot water supply, and provides a visible indication of whether water is flowing from the pressure release valve. If water is dripping from the tundish, it is important to call a qualified heating engineer to inspect the system and resolve any issues. Installation of a tundish must be carried out by a qualified heating engineer to ensure compliance with regulations and safety standards.