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WGordon · Oct 15, 2011, 10:16 AM

Last water heater 12 years old was just changed out because we started to run low on hot water. Thought that it just needed to be replaced because it was old so got a new Bradford White MI5036FBN 50 gallon water heater. We installed it and our water is even colder than it was with the old water heater. Don't get me wrong the water does get semi-hot with the thermostat jacked as high as it can go, but only for a few minutes (less than five) afterward you have close to room temperature water. Checked the heat traps and they look good. Didn't think that checking the dip tube (to see if it was melted) was necessary since the heat traps didn't look melted. It was tough to take out so I inserted a coat hanger to check the length and it doesn't seem as though anything broke. Hot and cold piping to the heater are OK. Water shut-off switch is on... What is the problem?

massplumber2008 · Oct 15, 2011, 11:12 AM

Hi Wgordon...

The first thing I would check is the voltage going into the unit... should have 2 legs at 110-120 volts each (for total of 220-240 volts). Sounds like one of the wires isn't powered... maybe?

Back to you...

Mark

speedball1 · Oct 15, 2011, 12:27 PM

Let me add a few more things that could cause your problem. You've removed the cold water and pulled and checked the dip tube?
Turning the power on before filling the tank would burn out both elements. Filling the tank until the water stopped coming in without first opening a hot water faucet to bleed off the air would burn out the top element and that sounds like that's what might have happened. Check the elements and if you haven't pulled the dip tube and inspected the flange you might do it now. Good luck, Tom

WGordon · Oct 15, 2011, 01:20 PM

Would this be the case even with a gas water heater?

It's a gas water heater, the only wiring on the unit is around the thermostat. Could there be something wrong with that? What do we do if one of the wires isn't powered?

massplumber2008 · Oct 15, 2011, 01:49 PM

If you have a gas water heater... are you sure you didn't pipe it in backwards? I know, seems like a silly question, but if you reversed the hot and cold on the heater itself the cold water would be feeding into the top of the heater and that would cause your issue, for sure! Double check that, OK?

In terms of the thermocouple... as long as it is lit, that should be all set!

Finally, are you sure the heat trap nipples aren't backward, too. The manufacturer could also have a defective dip tube so you may need to remove and check that as much as it stinks.

PS: Don't forget to turn that thermostat back to 120F.

Back to you...

Mark

speedball1 · Oct 15, 2011, 02:14 PM

Good one Mark! Reversing the inlets would give you the same symptoms as a faulty or dropped dip tube. Cheers, Tom

WGordon · Oct 15, 2011, 03:20 PM

Thanks guys... The previous heater was a Bradford White so I connected it exactly the same way it was hooked up previously. I touched the pipes to see if I was correct but the weird thing is that both pipes (close to the heater) are warm and the "cold" inlet pipe is hotter than the "hot" inlet pipe. If I continue up the "cold" pipe it is hot/warm to the touch about a foot into the pipe where the sprinkler system is connected.

If it is being hooked up exactly the same way as the last heater what's the problem? And should the pipe on the cold side be hotter than the other? I attached some pictures to see if I could help the situation. The pipe on the top in the first photo is a sprinkler pipe.

mygirlsdad77 · Oct 15, 2011, 03:36 PM

Couple things here. I see you didn't use dielectric unions. This of course wouldn't cause your current problem, but may lead to premature tank failure in the future. Now, did you solder the female adapters while they were threaded onto the nipples or pre-sweat them then thread them on? If you sweat them while they were threaded on, good chance you melted that dip tube. Even if the heat traps look fine, still a good chance the dip tube got melted. Time to pull it out and check it. You can use a long piece of ridgid wire with a small hook bent on the end to pull the tube.

speedball1 · Oct 15, 2011, 03:40 PM

Your pictures ere too dark to see much detail. Was there any heat applied to the cold water inlet? Did you solder in a 3/4" threaded adapter ? Let me know, Tom

massplumber2008 · Oct 15, 2011, 03:57 PM

Sounds like everything is doing its job... hmmmm.

First, the cold water pipe gets hot in all heaters, but only the first foot or two (heat trap nipples reduce this but will not eliminate all heat loss).

Next, check the dip tube as recommended. Then check the gas shutoff and make sure it is wide open. Here, make sure there isn't another shutoff in the gas line nearby that may be reducing flow to the water heater.

Finally, my only other thoughts is to check that the gas pressure is correct... could cause issue with the gas valve, or finally, my last thought here is that the gas valve or the inner burner assembly could have an issue right from the manufacturer, but that would require you to contact the manufacturer to troubleshoot their gas valve.

Good luck!

WGordon · Oct 15, 2011, 05:28 PM

Hey guys, I sweated the joints above the threaded part while it was on the heater. I pre-sweated the 3/4 threaded fitting.

Anyhow, I drained the water heater and I checked the dip tube... it is fine. Gas valve is fully open. The water heater heats up beautifully... water from the pressure valve is extremely hot. What's next?

Here are clearer pics of the assembly and the dip tube.

massplumber2008 · Oct 15, 2011, 05:51 PM

Hi Wgordon

I think I see your issue. I'm familiar with that gas valve and it can be a real pain to set the temperature properly.

Read all the instructions on that gas valve and it will show you how to set the proper temperature.

Pop back and let me know what happens, OK?

mygirlsdad77 · Oct 15, 2011, 05:58 PM

As Mark said, seems the water heater is doing it job. And it apears piping and dip tube are all good to go. Now, lets get a little more technical. Do you only have a shortage of hot water in a shower, tub, sink, etc. Or is there a shortage everywhere? If you are experiencing a shortage of water in one fixture, lets say a shower, when the hot water runs out, go to a sink and see if there is hot water there. This will tell us if the water heater is simply not producing hot water for whatever reason, or if you may just have a fualty mixing valve or single handle faucet cartridge. Doesn't look like you have a recirc line, so we just have to take this one step at a time. What I really want to know is if you get a good amount of hot water at some fixtures, but not others.

Mark, I think this gas valve is pretty simple to set. Maybe you are thinking it's a gas valve with led readouts, kind of like AO Smiths? Im assuming (since he said it was turned up all the way) that is is putting out pretty hot water, like I said, just assuming(making an etc etc). If its on very hot, you need to put it on hot and find out the real reason for lack of hot water. Of course, it may still be a bad gas valve, but if you are getting extremely hot water out of the pressure relief valve, that tells me that you have a full tank of hot water, and it should last you longer than five miniutes.

WGordon · Oct 15, 2011, 06:54 PM

We have hot water!! Problem: I was also remodeling the bathroom on the second floor. I left the pressure test cap in place creating in essence a recirculating valve. I want to thank everyone who pitched in to help us solve this issue. Special thanks to you who mentioned the recirculation valve as a possible issue. It got me going in the right direction. Thanks again to everyone!!

mygirlsdad77 · Oct 17, 2011, 04:07 PM

Thanks for the update. Glad you got it figured out. Take care.