Feelin' Handy

My wife called me yesterday afternoon and told me that our radiant heating system in the basement wasn't working.

What??  That system isn't even five years old yet!  Ugh.

I came home and checked it out.  Yes, the basement was colder than the 60 degrees we keep it at when nobody is down there.  Yes, the pumps used to circulate the water through the system were running.  No, the boiler wasn't on, so no water was being heated.  That was obviously the problem.

I remembered the plumbing contractor who installed the system telling me that it was set up so that when water was flowing through the boiler, it would automatically turn on.  When water wasn't flowing through the boiler, it would turn off.  Something was wrong with the boiler.

Ugh.

I took the front plate off of the boiler (after turning the gas off, of course) and took a look at it.  It looked pretty simple.  There was a grey box with a couple of buttons on it: Test and Reset.  I pushed the Test button and a red LED came on.  I pushed reset and the red LED turned off.  The power supply was working just fine.

A quick Internet search led me to the manual for the Takagi T-KJr. "Instantaneous Water Heater" and after looking at the manual for a couple of minutes, I decided to try cleaning the water filter.  I knew, however, that this would depressurize the system and it would let air into the system.  Both didn't seem like very good ideas, but by cleaning the water filter, I could try circulating water, and if the burner in the water heater came on, I would know that the source of the problem was fixed.  And besides, the manual said that "This procedure is highly recommended."

So I decided to give it a shot.  I grabbed a bucket and took out the filter.  There was a fair amount of sediment in the filter.  I rinsed it out thoroughly, reinstalled it, turned the power and gas back on, and turned on the nearest thermostat.  The burner fired up right away.  I had found and solved the problem.  Hooray!

However, by fixing the problem, I had created another problem--one that was really inevitable.  The gallon of water that drained out of the system while I was cleaning the filter let a gallon of air INTO the system and the water pressure in the system had dropped from about 12 PSI to zero.

At this point, I knew that I needed to bleed the air out of the system and I needed to repressurize the system.  Knowing WHAT I needed to do and knowing HOW to do it were two completely separate things.

So I went to the radiant heating panel to see if I could figure out what to do next.

Hmmm.

I saw eight valves, three spigots, three pumps, and quite the array of pipes.

I did some Internet searches.  Google didn't seem to be helping me out.

Hmmm...

I came to the conclusion that I needed to call my friend and former student, Kyle, and pay him to come and fix the air/zero pressure problem.  I left a message, and continued to puzzle over this little problem.

Hmmm...

I came to the new conclusion that if I knew the direction of water flow, I would know which of the three spigots to connect to the water supply and which of the three spigots I should let water drain out of to force the air out of the system.  I figured that the pumps would have some sort of marking on them telling which direction they were pumping the water.  They did...but the markings were back where I couldn't see them.  Google helped me out this time.  I searched for the make and model of pump and quickly found a diagram.

With this bit of knowledge, I quickly figured out how the water flowed through the system.  I headed off to Wal-Mart to get hoses--one long enough to reach from the water supply (cold water supply for the washing machine) to the radiant heating panel, and the other long enough to reach from the radiant heating panel to the drain on the floor.  I also needed a hose with two "female" ends.  They don't sell such a thing, so I bought a regular hose and a "female" end repair kit.  I cut the male end off of the new hose and attached the repair kit and I was ready to get the system working.

I closed all of the valves on the system, attached the hoses, turned on the water, and then, using the valves, I ran fresh water through the system, one section at a time.  I heard the air gurgling through the pipes and saw the bubbles exit the drain hose.  I also saw the little bit of dirty water (from the dirt I had dislodged when I took out the water filter) leave the system and go down the drain.

After running water through each section of the system for a few minutes without hearing or seeing any air bubbles, I was pretty sure that there was no air left anywhere in the system.  I closed the outlet spigot and let the water pressure build up (watching the pressure gauge) until it hit 12 PSI.  I closed the inlet spigot, and I ended up with an air-free, pressurized system.

The final test--I opened all of the valves (for normal operation), powered up the pump system and the boiler, turned on the gas, and then turned on the heat from the thermostats.

And EVERYTHING.  WORKED.  PERFECTLY.

I don't know how much it would have cost to have a repairman come and do the work, but I'm sure I saved a bunch of money.  But more importantly, I have the equipment and the know-how to maintain my radiant heating system!