Water Heaters - Bradford White NG fired 50 Gal W/H takes 4ever

I recently looked at a customer's HWH (Bradford-White NG 50 Gal) and found that it took nearly ..... 90 minutes to bring the water to about 140*:mad: .

I checked for sediment and let out several gallons of water from the bottom drain, I also let out water from the relief valve. It came out a bit dirty from the bottom, but I have worked on many 10+ year old HWH and NEVER got water coming out perfectly clean.

I checked for fire and it was fine; I did not even notice any difference when the NG fired furnace happened to kick on while I was watching the HWH. The fire looked nice and it was consistent to what I have seen on other HWHs, so I rule out any problem with combustion.

I went upstairs and removed the aerator/restricter from the bathroom faucet and put on the hot water and got real good flow, then I tried the cold side and got about the same amount. No noticeable restriction here.

After about 90 minutes the thermostat got satisfied (about 3/4 the way to maximum). The thermostat seems to be working fine because when turned down as it was heating up, the fire would go off. As it got hotter and hotter, if you turned it down the fire would go out at a higher point on the dial. It finally reached its set point at 3/4 to max and the fire shut off. If adjusted higher, the fire would come back on. The thermostat is working OK.

Why would it take so long to heat up? :confused: Are there mineral deposits somewhere acting as thermal insulation preventing it from getting heated quicker?:wall: IF this is the case----what is the cure?

I'm kind of stumped this time. I am on the receiving end here guys. :o I'm listening.

Keep it simple.

Charlie :coffee:

What is the setting on the thermostat?? 90 min from dead cold does not seem too rediculous for a 50 gal heater. Recovery from a shower in that time is a bit different.

I am no expert, but my old hot water tank, that was working off the boiler, used to take 2-3 hrs to recover.

When I replaced the boiler and hot water tank the plumber couldn't believe the weight of water tank (drained). He later cut it open and was just encrusted with hard water mineral deposits. It just looked awful.:blah:

I hope this helps.

Mark_ms

90 minutes from ROOM temperature (about 68*) since they had shut off the water heater and BEFORE I started it back up (it was only on pilot) the water coming out of the hot water side was about room temperature, (give or take) just to get up to near 3/4 to 'hot' on the thermostat. If you see NG (NATURAL GAS) water heaters frequently, then you know that very few of them have any graduations in degrees, they usually say 'warm', 'warmer' and 'hot'. Usually hot means about 1608 MAX with a thermometer. I was still able to hot my hand under the hot water for about 10 seconds, that's about 130* I figure. I could have held it longer, so it may have only been 115* or so. Anyway, 90 minutes for a 50 gal NG HWH to reach 120* is WAY TOOOOOOOOO LONG in my book! :wall:

I NEVER came across one that took more than about 30 minutes. ;)

Remember, this is a natural gas fired unit. Only raising 50 gallons of water about 60 degrees.

Any ideas. I'm even willing to listen to SIMPLE ones. heheheheh

Thanks,

Charlie:coffee:

Ummm. It's unlikely that the incoming water temperature was 68 degrees. Water heating costs commonly go up by 100% at the peak of the winter compared to the peak of the summer because the incoming water temperatures are a lot colder.


Might this have been a factor in what your noticed?

The HWH was off at least 24 hrs. and nobody used the 'hot' side of the faucets (except for an occasional accident when they forgot there was no hot water), for that period of time.

I assume the room to be in the area of 68* since the HWH is in the basement, and the furnace is right next to the HWH. But even IF the water was 40*, I think 90 minutes is a bit tooooooo long.

Has anyone out there ever experienced a 90 minute wait for hot water on a natural gas fired WH. In my experiences with NG HWHs I have found that 30 minutes is about normal for it to heat water to about 115* (give or take). Even 45 minutes would be OK, but 90 minutes? :mad:

Like I said, the thermostat works:) , the fire is 'nice' under there:) , it just takes tooooo long:mad: .

Is there any way for mineral deposits to be responsible for this? If so, is there a cure? Could it be something else causing the long heat-up time?

Ready to tell the customer to invest in another HWH, but cannot explain to them WHY.

I would rather try to fix this one.

HELP!:wall:

Charlie

Is there any way for mineral deposits to be responsible for this?

Yes, however the water would have to have a rather high calcium content. You might be able to remove the T&P valve and with the aid of a small flashlight inspect the central flue for scale build up.

If this is something that has been going on since the heater was first installed I would suspect the "retarder", the twisted metal strip installed in the central flue to be missing.

Have you "clocked" the gas meter when just the water heater is firing to see if the gas flow is the same as the nameplate rating?

10 minutes after the previous post the customer called me and informed me that it was working ok now. :thumbup: All I did was what I mentioned in my initial post, nothing more.

Maybe draining from the bottom helped in some way?:confused:

Thanks to those who tried to help.

HO-HO-HO-HO------HO-HO-HO-HO

( :cheshire: )


Charlie
:coffee:

furd:

Next time I have a service call to that house I will do that. I do other things for them besides plumbing, electrical, etc..., so I know I will be there within the next 30 days or so.

That's a great idea about looking inside the T&P tap for scale! :thinker: How would one de-scale a HWH?:confused:

Charlie:coffee:

How would one de-scale a HWH?

The same way as with a commercial or industrial sized boiler, with a citric acid solution.

Of course the cost to de-scale a residential water heater would be far greater than simply replacing the heater so it is a moot question.