Water heater on pilot

BoilerBoss

I have a customer that goes on a lot of trips and she's very conservative with fuel. She turns her water heater to pilot while she's gone and sometimes forgets to turn it back on when she returns. When she first uses the hot water, it's SCALDING. The water heater is only 6 months old and I've called Bradford-White with the problem and they say:

The heat from the pilot is greater than the stand-by loss of the water heater. It naturally overheats after a few days.

This one is hard to understand for me and the home owner. I've turned my water heater to pilot, come home from vacation and turned the control off pilot and WHOOSH, the burner comes on.

Any comments?

P.S. On my last visit, I turned the water heater to pilot, kind of expecting the burner to come on, but no, it didn't.

ratio

Sounds like a legit explanation to me. I'm a tiny bit doubtful, but one would think that the mfgr would have a reasonably accurate understanding of the standby losses, and the thermal performance of the pilot is easily calculated.

Does this model have the built-in piezo igniter? It should only take a few clicks to relight the pilot, Try turning it off before a trip, that should prove it.

If the pilot really does exceed the standby losses, it might be advisable to turn off even the pilot during trips. If the tank got so hot that the T&P valve opened, that could be bad in an unoccupied house.

HVACNUT

My parents had a standing pilot atmospheric CI boiler. I wound up turning off the gas valve in the summer because the basement got so hot.

ChrisJ

Does this heater of a damper in the flue pipe?
What's the insulation thickness? The typical 1" or is it a beefier 2"?

I recall Bradford White making a higher efficiency atmospheric heater with a damper in the pipe, but I don't recall if it used a pilot or what the story was. I just remember it being something like double the price of a normal tank heater.

Alan (California Radiant) Forbes

Try turning the unit to pilot and tripping the temperature control on.

Solid_Fuel_Man

I'm conservative with fuel too.... I dont own ANYTHING with a pilot.

Maybe a power vent, condensing model, or retrofit a HSI on the water heater.

ChrisJ

Solid_Fuel_Man said:

I'm conservative with fuel too.... I dont own ANYTHING with a pilot.



Maybe a power vent, condensing model, or retrofit a HSI on the water heater.

I didn't think you could use a pilot with a solid fuel.

hot_rod

Actually my gasification wood boiler does maintain a pilot of sorts.

The inducer fan pulses at a very low rpm ever few minutes to add just enough O2 to keeps some coals glowing. When you add more fuel, or the call for heat comes on they fire right back up.

Solid_Fuel_Man

That's cheating! But I know exactly what you mean. My draught is enough to keep my gasification boiler lit. The fan idle times just make more heat.

GroundUp

My OWB has a similar "pilot", there is a timer that the draft fan runs through and if there hasn't been a call for heat in 30 minutes, it'll run the draft fan for 30 seconds to keep the coals charged up.

As for the standing pilot in the WH overcoming the standby losses, I'm skeptical. I've got a cheap Richmond atmospheric WH at home which runs on pilot ~6 months of the year, as it's heated by my wood boiler all winter. The standby is probably a bit more with the Richmond, but even so- the needle on my LP tank doesn't move in 6 months of running the pilot. Say the standby loss is 1/2 a degree per hour, that would require the pilot to be putting out more than that. 30 gallons at 1/2 degree is 125 BTU/H. A 24 hour day is 3,000 BTU. 6 months is 545,000 BTU, or 8 gallons of LP at 80% Efficiency. These are VERY conservative numbers. To overcome that standby loss, we'd be seeing a minimum of 2-3% drop in the LP tank but probably close to triple that using the real numbers.

The Steam Whisperer

This sounds awfully fishy to me. If the pilot does exceed the standby loss of the heater, then Bradford White has a serious problem on thier hands.......the temperature control on the heater cannot adequately control the water temperature to prevent scalding and possibly the safety relief valve blowing off. I doubt they would make a heater that way, but you never know. I don't know what the codes say about that.

ChrisJ

> @The Steam Whisperer said:
> This sounds awfully fishy to me. If the pilot does exceed the standby loss of the heater, then Bradford White has a serious problem on thier hands.......the temperature control on the heater cannot adequately control the water temperature to prevent scalding and possibly the safety relief valve blowing off. I doubt they would make a heater that way, but you never know. I don't know what the codes say about that.

One problem is "scalding" in this case isn't a number. Some may call 115-120 this. Others would assume 140-160.

We also don't know the ambient temperature.

If the pilot alone is maintaining 120 in a warm ambient I wouldn't think that's an issue.

The Steam Whisperer

How hot the tank will get, depends on how much the pilot output exceeds the standby loss. If the ambient is quite warm ( like water heaters installed outdoors in warm climates) then the tank will get much hotter. I would expect that the codes would limit how hot the tank gets to about 115 to 120F when just on pilot to prevent injury, since the operating control cannot regulate this heat build up.

hot_rod

1/2 degree and hour is suspect, even in indirect tanks No way a tank with a flue in the center has that low standby.

The indirect standby loss is suspicious also Maybe if the tank is at 120 in an 80 degree room🤔

Solid_Fuel_Man

I'd guess 2-3 degrees per hour loss, but Chris has a point. What is true actual temperature of the water?

Also, I'm used to equipment being in a cool basement so draught and standby would be higher. People with stuff in a garage in warm climates would have different results.

Larry Weingarten

Hi, Pilots are supposed to be about 400 btu per hour. I’d have a look at the flame size. Also, the venting may not have adequate draft. And it couldn’t hurt to check gas pressure.

Yours, Larry

Lance

I have a Bradford standing pilot on a 4" B Vent flue height 35' tall.
All is normal. Problem we can experience in Pilot only situation is the tank is no longer maintained at normal temp and the flue gets cooler and reduces its ability to draft. Build up of heat is in the unit and surrounding air. Heaters are made to maintain a certain range and function. Just because we can use it differently does not mean it will behave normal. Vacation mode. Has anybody ever seen this laboratory tested with real data? I have never been curious enough to find out.
All I know is a pilot can generate enough air circulation to keep a basement dry. Our science that worked 60+ years ago saved us countless problems in service and replacement costs. Along came Mr. energy saver and now we shifted our direct costs to replacement and service at a 3 times greater need from our natural resources. Water heaters lasted 30-40 years, now we see they last 10-15. Progress? savings? I think not. If it were, why do they constantly keep changing things to find a solution?
Standing pilot heater. One moving part, usually never fails. No electricity needed. I would always pay more for one less thing to worry about any day. If we reduce water pressure in the mains 10 PSI, we reduce the leaks, failures and waste. Problem is we overbuilt the old plumbing systems' capability, boosted pressure to compensate making more problems instead of making a new system independent of the old.

mattmia2

How is it 1/2 degree per hour regardless of if it is 20 gal or 120 gal...

southernilfarm

Howdy,

New to this site after searching to find an answer - hope you all can help me.

I've got a Bradford White 40 gallon Propane water heater. Model number RG240T6X. It is installed in a recreational building that goes months between uses. In an effort to save a few bucks, I left the water heater on "Pilot" and forgot about it. A few weeks later, I was in the building and washed my hands. Much to my surprise, the water was HOT! I didn't take a temperature reading but it was too hot for a shower.

Is this normal? Sounds like it may be?

Thanks,
Mike

Solid_Fuel_Man

If you want to save money, turn off the gas to the unit if not in use for several weeks. Doesn't take long to heat up a tank of water.

HVACNUT

Did you check the water heater thermostat? Did someone else raise it? No, it's not normal for a pilot light to heat 40 gallons to 120°. Is the flue clear and drafting?

HomerJSmith

That's a hell of a water heater. Just think you can heat your DHW with a candle if you only quickly shower once every two weeks. The only need for the burner is for fast recovery. Hmmm.

Look put a thermostatic mixing valve on it and she'll be happy.

Skoptsy

Try checking your water heater thermostat and whether someone else raised it.

southernilfarm

Howdy folks. The same day I found this site and posted here, I sent Bradford White a note regarding my pilot light keeping the unused water heater "hot" over a period of weeks. The message, and their response follow.


My question:

Sent: Monday, September 30, 2019 3:30 PM
To: Tech Service
Subject: Pilot light question


Greetings,

Model number: RG240T6X
Serial number: PC39113461 D/N

Will this water heater keep water hot when left on "Pilot" for long periods of time when we are not using the building? This water heater is installed in a recreational building that goes months between uses. I've noticed there is plenty of hot water (not scalding hot, but hot enough for showers) even when the control is switched to "Pilot" for months.

My contractor who installed this system has retired and the vendor we purchased from referred me to you for this question. I'm trying to determine if something is wrong with the water heater.

Thanks,
Michael Clark

Bradford White's response:

Michael thank you for contacting us with your concerns . When leaving the heater in pilot mode with no water demand the stagnate water can certainly maintain hot water in the tank especially when considering the ambient temperatures in the room the heater is installed in.

If you need a new plumber you may try one of the local contractors that service our heaters through the following link -> https://contractorfinder.bradfordwhite.com/contractors


Mike Taylor
Tech Support