Lukewarm Shower Problem

Kate Knight, who lives in Brentwood NH eighty miles south southeast of my house, has a problem with her new shower valve. Let her describe it:

"Recently we had a new valve put in our shower which is bigger than our last one coupled with a water saver shower head. We also moved our toilet and put a washer dryer in there (don't know if that's relevant).

The guys did a great job. But now our shower doesn't get hot. So they came over and said we need to turn the water heater up to 135 F because the valve is bigger in the shower. Is there any other way to make the shower hot again? I'm nervous my kids might get scalded in their shower."

And since I'm a master plumber as well as a builder, I've got her answer!

Kate, almost every modern shower valve comes with built-in technology with respect to anti-scalding. Most valves need to be adjusted in the field to deliver the right temperature of hot water the customer wants. The factory settings often assume a hotter temperature than what is actually in the customer's home.

I'm shocked that your installers didn't know this and gave you bad advice about raising the temperature of your hot water. Do NOT do that. Your instincts were correct.

I'd go online - or hopefully the installers gave them to you - and get the WRITTEN installation instructions for that shower valve. They should give you step-by-step directions how to take off the decorative cover and get access to the adjustment screws that will allow you to get the right hot water you want in the shower.

Let me know what happens.

Reference: January 18, 2015 Weekend Newsletter