Trouble-shooting domestic hot water systems, part 2

IN LAST MONTHS column (pg. 30), we began the art of trouble-shooting domestic hot water heating system complaints commonly aired by unhappy homeowners. Here is the second part of this three-part series. The water in the shower never gets quite as hot as it seems it should be. This is an easy one to test. Wrap you self in Saran wrap, carefully poking holes for your eyes and nose, then adjust the shower

IN LAST MONTH’S column (pg. 30), we began the art of trouble-shooting domestic hot water heating system complaints commonly aired by unhappy homeowners. Here is the second part of this three-part series.

“The water in the shower never gets quite as hot as it seems it should be.”

This is an easy one to test. Wrap you self in Saran wrap, carefully poking holes for your eyes and nose, then adjust the shower and get in and see if it feels OK to you. If not, it probably has one of the code-required anti-scald shower valves, and it needs to be adjusted to the consumers’ needs.

Never adjust a shower to your needs, always adjust it to the consumers’ needs. Make them wrap themselves in Saran wrap too and have them get into the shower with you and see if it is the correct temperature for their needs. Don’t forget to properly dispose of the Saran wrap when you are done performing this service.

Just kidding about the Saran wrap, although I have heard of plumbers doing this in an attempt to satisfy a less than happy customer.

The best way to resolve this situation is to ask the customer to adjust the hot water in a lavatory (non-scald-protected) to the temperature at which he feels he would like his shower to be. Document this temperature using a thermometer with him observing the reading. Adjust his shower to this temperature and then add 5°F to this setting. Then, document the fact on the field service work order that you have adjusted the shower valve to this setting under the agreement and watchful eye of the consumer and then have him sign it.

They came, they felt, they agreed and they signed off to that fact. Your backside is now better covered than it would have been had you simply made adjustments and left. Soft tissue damage lawsuits are the most expensive in the world.

“The shower water temperature fluctuates wildly whenever anyone else is using water in the house.”

This is one of the hardest complaints to track down, because all the pipes are hidden in the wall. It generally has to do with the overall hydraulics of the plumbing distribution system. While the new shower valves are supposed to be pressure and temperature compensated, I honestly don’t believe the manufacturers thought anyone would flush a toilet in the same plumbing battery in which someone was taking a shower. I live in an older home without pressure/temperature-balanced valves, and we have a standing rule here. If someone is in the shower, no one is to use any water for anything else while that person is in the shower.

It is possible to adjust the drop rate of certain ballcock-type toilet fill valves to alleviate their pressure drop on the water system, but in some cases it can’t be done without affecting other aspects of correct toilet operation. It is also possible to adjust the stopcocks on lavatory valves to alleviate their pressure drop, but usually at a substantial consequence to the flow rate of the lavatory.

“The water temperature changes continuously during a shower.”

They get in, adjust the water temperature to a comfortable setting, and it changes continually. This is very similar to the situation with the circulation return check valve that I talked about last month. It is usually a situation whereby the hot and cold water are cross-connected either through an improperly installed faucet (pre-rinse spray with no check valves on the hot and cold, and the valves left on all the time) or, in some cases, it may be caused by an older-style single-handle cartridge shower valve that has lost its O-ring, allowing the hot and the cold water to cross-connect.

The solution to this one is simple enough. Find the cross-connection and eliminate it. Don’t forget to suspect the clothes washer’s solenoid valve. Finding the cross-connection is usually the hardest part. Good luck.

Tune in next month for the final installment of trouble-shooting DHW systems.

Mark Eatherton can be reached via e-mail at [email protected] or by phone at 303/778-7772.

TAGS: Showers Lavs