My line from tank to house is too small for a tankless water heater. Is it safe to move the regulator from the tank to the other end of the line where it enters the house? As I read it the pressure from the tank should be around 200 pounds so the pipe should be capable of handling much more pressure than that.

NO.

The regulator is attached to the tank for a good reason... namely that if you ever have a leak in the line somewhere, it will only leak at the regulated pressure (10psi? I don't know).

A high-pressure line that gets ruptured somehow (over time accidents happen) could empty the tank very, very rapidly. Also, a smaller leak could rupture the line explosively, as the gas is compressible and under pressure, which is very different* than a non-compressible (ie water) under pressure. A small leak could explosively rupture the line.

What I'm telling you is just my personal knowledge, I'm not a plumber and I don't install gas equipment for a living. Just the same I'm pretty darn sure you'd be violating code and worse, creating a potentially disastrous hazard by moving the regulator away from the tank.

It shouldn't be that hard to increase the size of the line anyhow.

Good luck!
~aaron



* find some writeups on the 'net about plumbing shop air, from a compressor to explain the difference. In short, people who are plumbing shop air with PVC are taking a real risk.

Do not ever mess with the propane regulator...
If you only have 1 regulator at the tank and none by the house where the line goes into then you have a twin stage system.. which means the regulator on the tank takes the tank pressure ( that will differ depending on the weather) drops it to 10PSI.. then drops it to operating pressure between 10"wc to 14"wc.
You have 2 options here... Have your gas company either switch yor system around to a 2 stage system which is where the regulator at the tank drops the pressure to 10PSI and that pressure runs to a 2nd stage regulator, which is usually located at the home where the line enters the house and make modifcations inside to increase capacity or the other option is to get 2 separate 100gallon tanks located in a closer proximity to where the heater is going to be and run a line large enough to handle the BTU load.
What ever you may do... just call your gas supplier///they should be willing to have someone comeout and give you a site survey and if they aren't willing to do for free.. threaten to switch suppliers.

Clearence from a rinnai water heater vent to a propane regulator

The project is to attach 2 40# propane cylinders to a Raypak 266K heater. This will heat my spa. I would appreciate any recommendations for a regulator. Someone said that I would need at the least a 13" wc regulator. No brand was recommended. Thank you.