Water heater explosion

Originally Posted By: wcampbell
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Stolen from another HI site:


This Ole House-Home Inspections
William A. Campbell TREC # 6372
Serving the Texas Coastal Bend
(361) 727-0602 (home)
(361) 727-0055 (office)
(361) 229-4103 (cell)

Originally Posted By: Blaine Wiley
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I saw that somewhere else here on the board this morning. And people wonder why we look for a T&P valve…

Originally Posted By: aroden
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I heard an LOUD explosion that appeared to come the garage - not a good way to start the weekend.

I went out and found water POURING out of the wall below my two year old natural gas powered Bosch on-demand water heater. When I cut into the wall, I found that one of my NEW Raupex water pipes (the cold water supply to the water heater) had burst just beyond the point where the Raupex connected into the rigid copper.

The water pipe had MELTED and burst. So I had the plumber out, fixed the pipe and cranked the water heater back up - the gas burners fired up even though there was NO hot water turned on inside the house. After a minute or so, the copper cold water supply pipe got too hot to touch - the heat had traveled up the copper and had melted the Raupex pipe.

Not once during this episode did any heat get anywhere near the t&p valve.

So after going to the Bosch website, I find that this is a COMMON problem - minerals in the water clog up the screen inside the water valve on the heater and CAN cause the unit to run continuously even though hot water is NOT being used.

GEE...thanks Bosch for LETTING ME KNOW!

Buried in their website is a service bulletin recommending that the valve be broken down and cleaned and/or rebuilt every two years or so.

I tore the heater apart and found ALL KIND OF MINERAL BUILD-UP. After I cleaned and blew all the mineral debris away and put it back together it worked just fine.

So if you ever see these things out there, you might want to make a note of what can happen to them after a couple of years and recommend periodic maintenance by an EXPERIENCED plumbing professional.

Of course, neither plumber I called out, knew a ANYTHING about these heaters - so I HAD TO REPAIR IT MYSELF. Again, thanks Bosch.

I don't know how many of these things are out there, but Lowe's sells them so there must be quite a few. And my little episode is going on my reports when I do come across another one.

Originally Posted By: dvalley
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David Valley

MAB Member

Massachusetts Certified Home Inspections

"Some cause happiness wherever they go; others, whenever they go."

Originally Posted By: kleonard
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Thanks for the tip Al. icon_idea.gif

I am going to go to Lowes and take a look at this unit.

I have yet to come across a "on demand" water heater yet. I read an article that stated they are supposed to be much more efficient than the tank type. Also much more expensive, But I also recall the ad stating that they are supposed to last much longer and most have a 10 year warranty..