Sometimes more hot water, sometimes less

Our water heater is a Bradford White 40 gallon gas heater (model MI40T6LN10-394). Our home is 14 years old and the WH was installed new by the original owner when the house was built. The WH itself is 16 years old, per the letter code at the beginning of the serial number and the code key on the Bradford White Web site.

Off and on for probably two years, we've had inconsistent hot water. Using hot water begets more hot water. Not using hot water for a while (say, 8 hours or more) results in less of it when you need it -- but 30 minutes later, there will be plenty. I work from home most days and my wife is usually at home, so on most days hot water is being used throughout the day. This is probably why this issue hasn't been more pronounced. It's definitely more noticeable if we've both been gone for the day, or longer.

A parallel issue we've had for about the same amount of time has been that our dishwasher (a Bosch) sticks at certain points during the wash cycle. We had it serviced over a year ago, and the technician tested the heater unit in the dishwasher and verified that it wasn't dead. The advancing of the wash cycle I guess is triggered by the dishwasher's thermostat, and without hot enough water, the dishwasher won't advance on its own. The technician said the likely culprit was that the water coming from the WH wasn't always hot enough. This would certainly seem to jibe with our own experiences with the WH, so although correlation isn't necessarily causation, it would seem to be the way to bet. (The tech also replaced the dishwasher thermostat as a cheap preventative measure, but the stalled wash cycles have still continued from time to time.)

I know that our Bradford White is getting on in years (our model had a 6-year warranty), but I'd love to squeeze some additional life out of it if possible, since we've got a number of other in-progress home projects clamoring for dollars.

I don't know if the tank has ever been drained, but I can tell you that we have not drained it in seven years of owning our home.

What is the preferred course of action here? Based on the research I've done so far, my assumption for first course of action would be to see if I can drain off any sediment, and replace the thermostat.


Thanks.

You may want to run some water out of the bottom first and see if flushing does anything for you.
Fourteen years is getting up there. My last two gas water heaters died at 15 and 14.
I just repaced my last one with a tankless unit. I'm surprised that Bosch would need hot water to advance. Most of the time, the water will cool in the pipes anyway. And most people I know turn on the dishwasher without running hot water first, so the first fill is cold water. I "do" like to run hot at the sink first so that I do get hot water for the first fill.

Thanks, Terry. We'll try draining out some water next weekend. Re: the Bosch dishwasher, it's the same age as the water heater, so not the latest and greatest, if that makes a difference.

SouthSound said:

Using hot water begets more hot water.

Click to expand...

That is a principle known as temperature stacking. You don't actually get more hot water, you get hotter water so use less of it.