Pro Handyman Blog

I see a lot of home inspections calling for a repair on the water heater TPR (temperature & pressure relief) drain line. The issue that the home inspector generally calls out is that the drain line is trapped, or has an uphill rise in it. This can be a dangerous situation because when the TPR valve opens it is either due to high pressure or high water temperatures. If the water and steam blowing from this valve finds resistance from the drain line, it may result in severe damage to the tank and anyone near it. For this reason the drain line cannot have any rise in it.

The biggest challenge is when the point where the drain line exits the tank is lower that the point where it enters the wall (in many cases the drain is run through the wall to the exterior of the house). This will mean you will have to either raise the tank (not likely), or lower the drain line in the wall. You will have to open the wall and lower the point where it meets the drain.

Sometimes it is an easy fix though. Many times the installer will use a long flexible copper line, and it is so long that he is forced to bend it every which way to get it to fit. If any of these bends reduce the size of the drain line, or cause it to have an uphill rise, it is a potentially dangerous situation. However, this can usually be repaired by turning the flexible copper line in such a way so that there is no rise in the line.