Water heater overflow pipe requirements install#

This interesting TPR test lever addition was explained by the building owner. The string was routed up towards the ceiling, over a horizontal plumbing line and back down to a termination in a nice knot a few feet above the floor. Less dramatic but scary, at a different inspection I found that a string tied through a small hole in the end of the TPR valve's test lever.

Her son, playing with friends in the basement, lost an eye when he and a pal opened the discharge lever on a heating boiler, scalding his face and ruining his left eye forever. Sobbing she told me that she was grateful that inspectors would routinely point-out this hazard. Noticing that a TPR discharge tube was missing on a heating boiler during a home inspection I pointed out this safety hazard to my client while the real estate agent nearby frowned at my 'old maid' trouble-making personality.

Water heater overflow pipe requirements install#

This might have been installed on a system for other reasons, such as connecting a hose to permit easy draining of pressure off of the boiler through the TP valve.īut it is in all events dangerous, illegal, and plain stupid to ever install a shutoff valve or any other sort of 'cap' on a pressure/temperature relief valve.īut how dangerous is it to omit a discharge drain tube on a TPR valve? The possibility of a scalding burn is obvious but do these accidents actually happen? To 'stop' an annoying boiler drip at the pressure temperature relief valve, the mechanic installed a short length of pipe capped by a drain valve which he could simply shut. Only a complete fool would do what we found on this boiler. The purpose of this drain line is to discharge potentially hot scalding water to a safe location so that a bystander is not scalded.Īt left we see a typical TPR valve installation (by the author) including the vertical 3/4' copper drain piping that will discharge any T&P valve spillage to the floor.Īn unsafe TPR drain line installation is shown at the top of this page. The Temperature & Pressure Relief Valve or TPR Valve on any heated appliance that contains water, such as a heating boiler, hot water tank, water heater, water cylinder, must have a drain line or discharge tube properly installed, routed, and made of proper materials. Temperature/Pressure Relief Valve Discharge Tubes & Drain Lines & Their Piping We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need. Here we describe the installation specifications for TPR valve drain line piping and we include an extensive list of discharge tube installation or condition defects, most of which are unsafe. These include hydronic heating boilers (hot water boilers), steam boilers, and all types of water heaters, both those that use a water storage tank or cylinder and those that heat water on demand such as tankless water heaters. This article describes the requirements for a discharge tube or drain line on temperature & pressure relief valves used on any appliance that heats water. We have no relationship with advertisers, products, or services discussed at this website. InspectAPedia tolerates no conflicts of interest.