Hot water lines!

Your water pump needs to move more water. Yes I would "try" Wersbo pex style tubing with "shark bite" connectors.

Let me know how it works.....move more water....

miketheboilerguy@aol.com

Mike;

Appreciate the reply---have got gobs of water volume and pressure--the unit has a bad habit of getting the water remaining in the unit extremely hot before the gas burner turns off--the "wersbro pex" tubing "with shark bite connectors" you describe

available in plumbing suppliers?

Thanks again!

Jim

Yes Ferguson supply. Any trouble finding them let me know I have some scarps around.

Mike

Check the operation of your water flow operated gas shut off valve it is probably sticking and not shutting down the main burner quickly enough. You can see this function by using the heater inlet valve on and off and leaving a hot water tap open in the house, observe the burner flame if it hangs on after closing the valve then that is your problem. It should be stripped down cleaned and lubricated.

Garth;

I figure the problem has to be in the contol circuits because this unit does strange things--Actuall it need to go back to the manufacturer since it's new and has never run right since day one.

We have another unit which functions properly however both units have an extremly high temperture at the hot water outlet immediately following shut down which is causing the hot water line between the unit and cpvc (a 20" steel braided line commonly used in sink hot and cold water lines connected between the faucet and the supply lines) to blow off it's fittings.

Since this sudden rise in temperture , immediately following shutdown, seems to be inherant in both the gas and electric units, I'd feel more confortable with a differant type of supply line capable of tolerating the extreme temperture rise.

I guess I need to go to our local plumbing supplier to see if such a line exists.

Thanks again for the info.

Donzi

Would use of an expansion tank handle the fluctuation?

The valve that regulates the gas uses the difference in water pressure to control how much gas is burned to heat the water. If your supply side has 40 pounds pressure and the downstream side (faucet side) has 40 pounds pressure, which it should as soon as the faucet is shut off; the valve should instantly shut off the gas. That being said, let me clarify that some manufactures do allow a slight delay in the gas shut off...but nothing that will raise the pressure to cause the problems you are having. As Garth said, the valve appears to be sticking.

You shouldn't have to be going to the extra expense and effort to make the piping hold together. The valves have a problem and in my opinion it's a dangerous problem.

My opinion, again, is that you contact the manufacturer and give them the option of fixing the problem immediately or they can answer to the proper federal agency and face the prospect of having all of their units recalled for a serious safety defect. Don't let them play games with you. If they are a good company, they'll instantly start the process of taking care of the problem, if not, give them about 10 seconds to make the right decision and call the feds if they don't.

I'm not advocating being nasty with them, just plain and firm.

Randy;

You're absolutely right--after the last episode (the burner stayed on after the water was shut down resulting in the water boiling, the pipes clankin like they we're going to explode and steam coming from the washing machine), it's a wonder the washer hoses/pipes and all didn't explode and someone getting scalded--since I didn't trust the unit I was right on top of it and shut off the gas and kept cold water running through the lines until they cooled.

I then immediately contacted the supplier and gave them the option of repairing the unit,replacing it or returning my money.

I have (at my expense) replaced the unit with another unit (different mfg) since they didn't seem too concerned with my problem and we were just plain scared it would burn the house down or scald someone-I've worked with gas units for years but this one folled me at every turn.

PS-- The expansion tank suggestion offered by a previous respondant does make sense, even with the units operating properly, since there is a measurable increase in tempature on the output side, with either gas or electric units, immediately following supply water shut down. Could save the plumbing!

Thanks for the input!

Donzi

A thought to consider.

My company installs alot of tankless water heaters and in many cases (and to meet recent code changes) we need to install small expansion tanks on the outlet piping. This a cheap item that is easy to install. I would try this before pulling the unit.

As you know it will act like a fat spot in the pipe and should take that sudden rapid expansion.

Mike

Mike;

Thanks for the info--are these expansion valves the same units we use for washer lines that experience sudden shock from water shut down (selonoids)?

Donzi

MIKE,GARTH & BWIRE

Hey guys---found one of the problems--Got thinkin about the difficulty I was having , even with a new unit (won,t keep temerature steady although it doesn,t explode), and you know how us engineers think--being on a well, the pressure ranges from 40--60lbs and this is driving the control (flow) crazy---went and installed a pressure regulator and it set it for 45 lbs --set the pump at 50--60 lbs--now the temp is steady, the unit doesn,t shut off in the middle of your shower (high temp protection). Anyone installing a tankless system should install a pressure regulator also or the system won't work properly if at all and could be dangerous. Unfortunately the manufacturers don"t specify this--you have to find out the hard way.

This won't fix the first unit I originally posted for help-(mfg defect).

These lines may be fine now that the temp is under control !

Thanks again for the info.

Donzi