Plumber makes final connection, Impressed me, not so much

Generally I am a fan of building codes that keep the public safe.  It is great that only qualified people do things like install foundations, chimneys, high voltage lines, etc.  So I was not that disappointed when I learned that I had to hire a professional plumber to make the final potable water connections for solar hot water system.

I have changed my opinion.

The idea sounds great in practice, but the execution is not always a guaranteed success.  Let me share with you my experience with the plumber.

Firstly, the task was very simple.  Break open the feed to the existing fossil fuel hot water heater, route it to the solar hot water tank, then route it back.  The idea is that the solar hot water system acts as a preheat for the existing furnace based tankless heater.

My preferred plumber (Plumber 1) wanted $1100 to do the job.  This is impressively expensive for a couple of hours of work.  I tried to hire him, but he stopped returning my phone calls due to many "no-heat" calls from a freak fall snow storm that knocked out power to many homes in the area (including mine for 28 hours).  After a while, I called on Plumber 2 that only wanted $700 to do the job, fine, I hired him.  By the time it was done, he charged me $1000 for a crappy job, but I paid him anyway.  I really should have waited from Plumber 1 due to past good experience with him.

The best thing that can be said is that the system "worked" after the plumber left and the job site was left very clean.  Unfortunately, the quality of the work could have been much better.  Let me enumerate the ways that the plumber "failed" (in my humble opinion).

FAIL 1: The Backflow Preventer
The plumbing inspector required the plumber to install a backflow preventer for some unknown reason.  Perhaps there was concern that the non-toxic propylene glycol might work itself back to the street under some impossible scenario.  Of course, that would not help us here in the house.  If the propylene glycol leaks, it will come right in to the hot water supply and we will likely drink it.  That is not much of a problem since it is non-toxic, so I don't know why a backflow preventer was needed.  Also, if this had been a fossil-fuel fired heater, no backflow preventer would have been required.  This is clearly a case of fear of the unknown, but shouldn't have been a big deal, if it was installed correctly.
  The backflow preventer should have been installed for the whole house water supply, however it was installed just in the hot water feeder line.  The resulting back-pressure made the hot water supply pressure very low while leaving the cold water supply pressure high.  The result was that it was impossible properly adjust the temperature of the shower without micron precision on the hot and cold water taps. 

So I removed the backflow preventer and installed a short length of pipe instead.

Upon removing the backflow preventer, it became clear that it was plugged with plumbing putty or some such material as can be seen in the image.  It was almost completely plugged.  What kind of plumber does such lousy work?  I thought this might have flushed out of the new hot water tank and then perhaps be the fault of the tank manufacturer.  However the backflow preventer is before the hot water tank.  So this material must have come from the plumbers new work.

FAIL 2: Can't close 1/4 valve.
If there is a 1/4 turn ball valve in the existing plumbing, you would think the plumber would know not to run pipes in such a way that the valve cannot be closed.  As can be seen in the image, the yellow handled full port ball valve cannot completely close because it now hits a pipe.  Nice work.

FAIL 3: Tempering valve defeated
If you are not a plumber, you might not have heard of a tempering valve.  This is an important piece of safety equipment in your home.  If you have a furnace (or boiler) then it is possible that it could malfunction and produce seriously hot water, e.g. 210F.  If this came up your pipes into your shower you might be badly scalded.
   To prevent this, a tempering valve is installed.  The tempering valve takes in both hot and cold water, as shown in the picture.  If the hot water is above a certain temperature, the tempering valve mixes in a small amount of cold water to reduce, or temper, the water temperature so you are not scalded.

However, my plumber managed to connect hot water to both sides of the tempering valve making is dangerously useless.  He plumbed the solar hot water into the cold port of the valve, and furnace hot water into the hot port of the valve.  The result is that the tempering valve cannot function as intended.  This is probably due to the plumber's lack of familiarity with solar hot water systems.  Alternatively, perhaps I should had developed a plumbing diagram and given it to the plumber.  That seems a little silly for someone that is supposed to know how to do this, but there you have it.

This is really a double fail because the inspector didn't catch this error either.

FAIL 4: No Unions or 1/4 turn shut off valves
This might be a bit of a nitpick, but here goes.  As recommended by the manufacturer of the hot water tank, I installed unions and 1/4 ball valves  just above the hot water tank on the solar loop.  This allows the tank to be disconnected if service is needed.

However, the plumber defeated my efforts by not installing them on the potable water side of the tank.

So if service is needed on the tank, I will need to cut the copper lines on the potable water side.

Fail 5: Pretzel Plumbing
There is a certain art to plumbing.  A well done job not only works, but it looks neat and clean.  The plumber only had to run two lines and inexplicably he didn't run them along the same path.

As can be seen in the image, the cold line (blue) and the hot line (red) are not run along the same path even though they easily could have.  This would also have avoided the cold line running into the 1/4 turn shutoff valve.


All in all, the whole job was pretty disappointing and only barely functional.  The work was neat and clean, but the plumber failed in the five ways shown above.  He also seemed quite uncertain about whether or not an expansion tank was needed and ultimately installed one even though he worked to try to convince me that a tank was not needed.  All this difficulty occurred despite A) hiring a pleasant experienced plumber and B) getting a personal recommendation to hire this plumber.

I guess tradesman, in general, are not big thinkers.  They do what their fathers and grandfathers have always done, no matter if it is good or bad, unless it totally and utterly fails to work or the law requires something new to be done.

Wish I had done the plumbing myself and ultimately will probably remove all of it and install my own plumbing correctly.