Replacing furnace vent

[Duane N]

I'd also look at the slope of the exhaust and intake PVC pipes for the furnace.  They are supposed to slope back towards the furnace.  

Glad you found the main issue.

[R Clark]

Have you spoken to the installer?

No, I just took the thing apart yesterday afternoon.  I'll be sending the pics and my findings over to the firm's owner.

I'd also look at the slope of the exhaust and intake PVC pipes for the furnace.  They are supposed to slope back towards the furnace.  

Glad you found the main issue.

Thanks for pointing that out.  I didn't know that, but I looked again and see that the spec calls for minimum of 1/4" slope per 12" of horizontal run on the venting.  I am not planning to make any changes other than the last couple of feet going through the sill and the exterior portions, but I'll check the rest of of it.  The fix will require me to splice some new pipe inside the house which will extend far enough outside the house.

Overall, based on what I've found, the installers failed to on these points:

-  They didn't install the intake and exhaust termination vents a minimum of 12" above expected snow line.  For here, that's about 24" above grade.

-  The termination vent fixture used was inappropriate for this application and it was installed in a way that caused long term damage to the materials around it.  Maybe they didn't know what the moisture and gases would do to Hardie Plank, but that's a common building material.  Further, it was installed so that the warm, moisture-rich exhaust was forced onto the cut edge of the hardie plank at that spot.

Argh.  This is not an expensive fix, and it's not even particularly hard.  But when you spend a lot of $$ for a new system, you expect it to be done right.  There were other issues with the installation that caused some rework right up front as well.

[srv52761]

...... Argh.  This is not an expensive fix, and it's not even particularly hard.  But when you spend a lot of $$ for a new system, you expect it to be done right.  There were other issues with the installation that caused some rework right up front as well.

My brother-in-law did hvac for 40 years before retiring.  When I invested in a new system I called him for a recommendation on brand to buy.  He said I was asking the wrong question.  He said while there may be some difference in brand, the biggest issue wrt to call backs was the installer.  Some brands require the installer to be certified in their brand and models, some will let anybody do the installation.

Said to invest my time to find the best installer and then trust their decision on brand, but it was the quality of the installer that was driving force for satisfaction.

[R Clark]

To close this out, here's what I did:

Demo'd the work space:

   

Put PVC trim board in as the "block" for the intake and exhaust vents.  Since there are a number of different entry points for various things right in the vicinity, I only cut back to the solid plank siding on each of the two Hardie planks affected.  For the plank with the PVC block, the affected area was 23" wide, centered on the two pipes.  The plank on bottom was also affected, but not nearly as much.  The side on the left is a pre-existing seam with one of those plastic "seam shield" thingies on it.  (Sorry for the technical discussion.)  The right side of that bottom plank went over to where I found solid paint again.  All exposed edges of the planks were buttered with acrylic latex caulk with flashing behind for vertical seams.  The top of the PVC plank is Z-flashed.

   

Final shot.  Installed 3" PVC pipe in a Tee configuration as described in the installation manual.  The intake inlet and exhaust port are about 24" above grade.

   

As for going after the installers; the HVAC company changed ownership about 4-6 months ago.  I still sent a letter describing what I found.  I won't get any satisfaction besides telling the new owner he likely has a training/quality control issue if they haven't already addressed it.  After the initial install, I had issues with the brand new unit on the first weekend as the thermostat wouldn't control the unit.  A couple weeks later, had issues that cropped up due to improper pressurization with refrigerant at install.  13 months after install, the A coil failed when a soldered seam let go.  And now this.  I already told the previous owner that I had second thoughts about whether or not I picked the right company to do this work.