Thx for the reply.
-Picture’s of what specifically? I have tried uploading some pictures previously, but are denied because the file is too big.
-I’m not familiar with what a gas takeoff is; unless my propane supplier tech’s did one when they were out on 4/12?…IDK
-I installed the new Takagi 310U unit (LPG conversion) as it fit perfectly were the 21 year old Takagi TK-3 was- no adjustments were needed for mounting, the exhaust vent stack or LPG flex line. I did install some isolation valves; the old water heater did not have them.
Since 3/26 (day of initial fire-up) the unit has fired up 11 times and long enough to take a bath and 6 showers, so it has worked - just not consistently.
A new 2nd stage regulator was installed this past Tuesday and a new gas valve assembly and LPG conversion kit installed yesterday. Gas valve and conversion kit were sent by Takagi.
After trying to fire up the unit yesterday ( it did fire up once out of about 20 tries) & talking with Takagi yesterday, they did initiate a return authorization to get me out a new unit.
I guess they came to this conclusion after me calling them 11 times overall and them trying to troubleshoot what the problem could be with no solution.
Some of my questions are:
- are these new units that finicky/sensitive to pressures changes within the delivery line?
I can take an inlet pressure reading at the water heater at 8:30 a.m. at 38° and it’s at 11.10”wc.
I can take another reading at 1p.m. when the outside temperature is higher and the gases have expanded and get a higher reading on the manometer.
From the newly installed 2nd stage regulator ( that read 10.64” WC at it’s port) , the LPG iron pipe runs in the rafters of my house that has a metal roof, so it’s gonna get pretty hot up there. With the hotter temperatures expanding the gases, are these fluctuations in pressures going to make the new unit with newer technology (PCB,sensors,etc) run erratically?
The old water heater ran for 21 years until its previous issues.
I’m just wondering if my older LPG supply line is not adequate for a newer water heater with more sensitive technology(?)
In looking at the old TK-3 installation owners manual, it doesn’t have the requirements of measuring pressures that this newer unit has.
That’s why I have considered ditching the new unit & replacing the heat exchanger and burner in the old unit that were cruddy and corroded and give it a go.
Very Frustrating
* Some of you may be wondering why this whole process is taking so long.
I live in the mountains of Colorado and getting any kind of technician or services out to me takes a couple of weeks in scheduling with the service providers & getting on their waiting list.
ok. the gas take-off is designed to makes sure you have enough gas.
old Takagi TK-3 required 199,000 btu
new Takagi 310U has a slightly lower rating at 190,000 btu.
So you shouldn't have any issue with volume.
Look in the handbook. there should be a dip-switch for high elevation. You mentioned Colorado. Did you flip the dip switch for high elevation?
You mentioned uneven gas pressure. Have you checked the regulator on your LP system? It sounds like you may have already replaced it and calibrated the pressure.
Everything here sounds like you have a bad control board. I suspect swapping the unit is going to solve your problem.
if you haven't done so already, sit down with the booklet and read the entire booklet from front to back. If you have a new unit, typicaly the only thing that can go wrong is poor gas flow or your fresh air inlet isn't providing adequate fresh air. CHECK THE REGULATOR. a 1/2" regulator only feeds 140,000 btu. You may need to increase the size to 3/4"
If you used the old fresh air and waste piping, Push something all the way through to confirm that there's nothing blocking your fresh air.
Your water quality. Some areas of Colorado have lots of calcium in the water. Take the filter out and see if it's clean (it should be, it's brand new). If you have issues with water quality, you may need to install a filter before the water enters the tankless.
If the new Takagi doesn't solve your problem, I would install a Rinnai or Navien instead. Depending where you live in Colorado, if you lose power with any regularity, I would install a small inline UPS so you still have hot water when the power goes out.
Thx for the reply.
Dip-switch settings:
1on/2off for LPG
3-4-5 on for elevation range 7,501-10,100 ( my area is 8,700)
6 on, 7-8 off for single exhaust vent & room-air intake.
I don’t think there’s any blockage on the exhaust vent, for when I’m troubleshooting with the front water heater cover off, when there is a breeze outside, I can feel a downdraft coming down the vent stack & then going through the water heater body. The vent stack is a straight 10’ piece.
I put a 90° elbow (with window screen covering it’s hole) on the air intake port.
Uneven gas pressure reading’s occurred when I was taking manometer pressure readings. I have just found through trial, with the plastic tube attached to the gas inlet port, that if I bleed lpg through the small plastic tube that will attach to the manometer, that releases the pressure & then I get more normal readings- so, problem solved there.
& yes, a new 2nd stage regulator was installed this past Tuesday: 10.64”out of its port.
As far as the water filter , that was clean.
While the tech’s were out, we covered all the basics: water filter, spark out of the wire connecting to the igniter rod, cleaned igniter and flame rods. Checked for loose connections on the computer board. Oooftah!
Also-
Latest INLET port readings earlier today, when firing up the unit (4 tries) - avg. static readings of those 4= 11.33”. Average reading when water heater was under load, cycling & trying to fire up=10.72”.
The manual indicates the difference of static to dynamic should not exceed 1.5”
So the numbers fall within that spec.
So I know the unit is getting air and spark; the only thing that might be questionable is fuel.
I’ll call up Takagi tech support & ask them this:
If after the unit has cycled and goes to trouble code 111, if I quickly pull the combustion chamber tube from the combustion chamber connection port, should I be able to smell LPG? and if not, is that a definite sign that fuel is not getting to the combustion chamber?
You mentioned a bad control board.
I hope that is the issue and a new unit will solve the problem, although I’ve gotten my hopes up b4 when changing out the 2nd stage regulator and then swapping out the gas valve assy. Lol.
Thank you again.