Hello,
I recently had 2x 50 Gallon tanked units replaced with a single Navien NPE-240S in my attic. The work completed by a licensed plumber, home is located in TX and I confirmed the plumber's active master plumber license with the Texas State Board of Plumbing Examiners.
The unit puts out hot water for the whole house fine, however I did notice a few details that I wanted to bring up with the plumber but wanted to do a sanity check here first to make sure its justified.
1) The framing is 2x4's with with the unit hung with drywall screws, with the bottom of the tankless unit secured with a single drywall screw.. The plumber reused the existing drain pan that was in use for the tanked units, even though he brought a new tankless drain pain for the install but never installed it (The new uninstalled tankless drain pan was left in the attic, along with a few tools he left behind). Because of this the framing is slightly angled, although the unit itself is straight. It just looks a bit sloppy.
2) Reused existing metal flue pipe for tankless exhaust. Will this corrode over time since the exhaust gas of condensing units tend to be more corrosive?
3) The hot and cold lines (these are bendable copper piping, not sure of the technical term) were moved lower to accomodate the lower connection points of the tankless units vs tanked units. However these lines were not secured anywhere and are just resting on the rafters. The area where they connect to the Navien unit the hot water line is actually rubbing against the gas line. Because of this when using water, the pipes move in the attic and tap the gas line. Not sure the implications of this over its 20 year life span if these pipes are not secured.
I'm thinking securing lines and possibly installing a water hammer arrestor/pressure regulator kind of device would help prevent this movement in the pipe.
If I am taking a shower and washing machine is on, when the washing machine water valve turns off it causes the water pressure in shower to increase and decrease in a wave like fashion which matches up with the movement in the pipes in the attic.
I have attached pictures of the install.
I recently had 2x 50 Gallon tanked units replaced with a single Navien NPE-240S in my attic. The work completed by a licensed plumber, home is located in TX and I confirmed the plumber's active master plumber license with the Texas State Board of Plumbing Examiners.
The unit puts out hot water for the whole house fine, however I did notice a few details that I wanted to bring up with the plumber but wanted to do a sanity check here first to make sure its justified.
1) The framing is 2x4's with with the unit hung with drywall screws, with the bottom of the tankless unit secured with a single drywall screw.. The plumber reused the existing drain pan that was in use for the tanked units, even though he brought a new tankless drain pain for the install but never installed it (The new uninstalled tankless drain pan was left in the attic, along with a few tools he left behind). Because of this the framing is slightly angled, although the unit itself is straight. It just looks a bit sloppy.
2) Reused existing metal flue pipe for tankless exhaust. Will this corrode over time since the exhaust gas of condensing units tend to be more corrosive?
3) The hot and cold lines (these are bendable copper piping, not sure of the technical term) were moved lower to accomodate the lower connection points of the tankless units vs tanked units. However these lines were not secured anywhere and are just resting on the rafters. The area where they connect to the Navien unit the hot water line is actually rubbing against the gas line. Because of this when using water, the pipes move in the attic and tap the gas line. Not sure the implications of this over its 20 year life span if these pipes are not secured.
I'm thinking securing lines and possibly installing a water hammer arrestor/pressure regulator kind of device would help prevent this movement in the pipe.
If I am taking a shower and washing machine is on, when the washing machine water valve turns off it causes the water pressure in shower to increase and decrease in a wave like fashion which matches up with the movement in the pipes in the attic.
I have attached pictures of the install.
