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pinballlooking 09-16-13 12:46 PM

My next project natural gas tankless hot water heater.
I just got delivered a Takagi T-H3-DV with 0.95 energy factor. This is a condensing unit so it just vents with 3” PVC pipe.
I am moving my tank from the attic to the garage. I have copper pipe now but I think I will try my hand at installing Pex. I am going to add a return line for the recirculation pump. I have an aquastat and a trimmer for the recirculation pump. I am going to put contact switches on the bathroom doors and use my home automation to turn on the recirculation pump 10 min when the bathroom door closes.

Daox 09-16-13 12:54 PM

Very nice unit. What are you currently using for hot water?

pinballlooking 09-16-13 01:01 PM

I have a Bosh AquaStar 170V. My family has grown since we put in that tank. It does ok but we could use more GPM now. My old unit has a pilot and was about 80% efficient not too bad. It also does not keep the water at as a steady temp as the new electronic controlled tanks.

The attic install was a mistake. It has a couple 60 watt bulbs that have to keep it warm in the cold winter. They are temp controlled to turn on and off but if the burn out it will freeze the hot water. This is just a bad setup and I am going to change this.

Daox 09-20-13 11:53 AM

Where is the new water heater going?

pinballlooking 09-20-13 12:03 PM

I am going to put it in the garage. This will shorten the hot water copper by at least 30 feet.
It came with a free isolation valves and pressure relief kit.
But that did not ship until today.

Daox 09-20-13 01:27 PM

Interesting you should mention the freezing problem. I have a Bosch Aquastar 125B (on demand gas with a pilot light) which I am not currently using. I got it for a real deal because the previous owner had it in their cabin and their main form of heat was a fireplace. Well that fireplace sucked in so much cold air through the water heater's exhaust pipe that it froze up and cracked the heat exchanger. They had it repaired, but decided to go with an electric hot water heater after that.

pinballlooking 09-20-13 01:50 PM

If you ever need parts you can still get some here.
Bosch Aquastar 125B Repair Parts / 125FX Repair Parts Tankless Water Heaters. Repair Parts for 125B & 125FX
I just installed a new water valve rebuild kit on my old one last week.
It is doing better now this bought me some time so I don’t have to rush putting in my new water heater

Daox 09-20-13 02:10 PM

Thanks. I believe its in running condition, I'm just decided to go with a smart electric on demand hot water heater instead due to my solar hot water setup I have in the works. I still might use it as a backup heat/boiler though. The efficiency isn't amazing, but it was like $125...

pinballlooking 12-30-13 09:57 AM

1 Attachment(s)
0.95 energy factor with no more pilot light burring gas. No more water in my attic and worrying about it freezing up there.

I installed my tankless water heater this weekend. This is the first time I have used MAPP gas for soldering copper. This stuff is so good I will never go back to propane. This is the first time I used PEX. WOW this stuff is such an improvement I just love this stuff.

I put in two Tee’s with PEX valves on the hot water at both ends of my house for a return line. I put in a Tee and a PEX valve at my hot water tank. I just need to run PEX and pipe insulation for the return line and put in a recirculation pump.

I was going to leave my old tank in place because it does not require power to run and only use it when the power goes out but it would not pass code I do not have enough gas supply to run both and no way to guard against this from happening. So I took disconnected the old one.

The new tank requires power to operate so we will not have hot water when the power goes out. I am going to charge a car battery with a solar panel. I bought a real sine wave inverter just a little bigger than it will require to run the new tankless unit. I need to experiment with how long the battery will last with my new inverter.

The new recirculation will have a aquastat and will be hooked up to my home automation.
The bathrooms we have new commutation light switches. When you turn on the bathroom light it will kick off the recirculation pump for a certain amount of time.

Daox 12-30-13 10:07 AM

Looks like a nice clean install, very nice.

Do the instructions/manual say how much power it draws?

I know some of the tankless gas units used a bunch of D cell batteries... I doubt it draws much power.

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