Changing the circulator pump on the hydronic system

I wake up on Monday morning and find it a little cool in the house.  No matter, I’ll eat my breakfast and hit the elliptical.  The floor is a little cold to me when I’m doing my pushups.  No matter, I figure it’s just something I’m not used to.

Then I go have a shower and when I hop out I think “Dang, these tiles are colder than usual.”  I check the thermostat and sure enough, it’s set for 72 and it’s sitting at 66.  Aww man!  What a way to start the Monday morning.

I go downstairs to inspect the damage.  The boiler is working fine and I’m getting hot water which is a good sign (the boiler heats both the radiators as well as the indirect water heater in the house).  So for some reason, there is no hot water going through the radiators.  I check the house for any leaks and see nothing.  I stare at the array of various pipes heading in and out of the furnace.  I consult our good friend Mr. Google.  At the end of the research, I’ve determined that if no hot water is going into the entire house, there is a circulating pump out of whack.  Considering I have two that feeds the radiators and I know I changed one of them a few years ago, I figure it’s the other one that’s the culprit.  That’s my hunch at least.  If it’s something else, Lord knows what the heck it is.

I call up a well known plumbing supply store in town and ask if they have the Bell and Gossett NRF-22 in stock.  They do not but they say that they have the equivalent of the Grundfos up15-58fc.  Sounds good to me!  I ask what time they are closed that day and I head into town with the knowledge that my baby woke up shivering in the night and Vero had to take her into bed for the night.  It is my mission from up high to get this thing working!

It’s a 20 minute drive for me to get into town and when I get there, I’m pretty bummed to find out that the part isn’t even in stock!  Clearly, this is my fault as I didn’t explicitly ask “Do you have this item in stock?”.  I guess me asking “Hey, what time do you close?” and “I’m on my way in.” has nothing to do with an item being in stock.  The client service person tells me the equivalent pump is coming in tomorrow so I get her to put one on hold for me.

I drive home and realize that I really need to figure this problem out today.  So I start looking for other plumbing supply stores.  After an hour of calling up random shops from Google Maps, I stumble upon another one and they have the equivalent in stock!  Bonus!  I head back out to pick up this pump.  Irony was shining on me as the supply store was literally across the street from the other shop I had gone to.  If I had just stopped, looked around the street and saw a giant “Plumbing Supply” sign, I could have saved myself a trip.

No matter, I walk in, grab the pump, make sure that it’s the same dimensions and the bolt pattern is correct.  All matches up and I head on home.

Taking the old pump off of the hydronic system turns out to be a slight mess.  I had shut off all the valves in the system and opened the drain valve and nothing came out.  Thinking that for some reason that maybe there was no water in that part of the system anymore, I figured the only thing I could do is take the old pump off.  Of course, water starts spraying everywhere (which I expected) so the bucket was taking in a LOT of water.  After awhile it finally subsided and I was thinking that I must have drained way more than what was in the pipes surrounding the pump.  I looked a little closer at the entire system and after peeking my head up into the suspended ceiling, I realized there was another valve to shut off and that valve was the water intake valve which was constantly pumping water into the system if it’s missing!  Ha ha, no wonder there was a lot of water coming out.  It never would have ended!

With that, I take the pump off and notice that the bottom pipes are still full of water.  I realize that the drain valve must have been clogged all along so I take a coat hanger, jostle it around and sure enough, a load of sediment comes pouring out all over the place and the system is finally drained.

I work at putting the new pump in and then it dawns on me. 

It’s NOT the equivalent pump.  Sure, it fits good, but the wiring is different.  My old model allows for daisy chaining…a set of wires into the pump and and a set of wires out to power the next pump in line. 

This pump only had one inlet for wiring.  As if!!!

I call the store back and they say the pluming guy is on lunch break.  Instead of waiting for a call back, I figure I might as well bring the old and the new pump into the store so they can see what I’m dealing with.  Trip #3 into town and it’s now 2PM and no heat in the house.  My anxiety is starting to raise.

I get to the supply shop and explain my predicament.  The instruction manual does explicitly say that there are certain models that allow for two wiring inlets but the guys at the shop have no idea what model that is.  They suggest I try and just cram all these wires into the same hole.  So now I have to get six wires down one hole.

With no other options, I head home feeling defeated.  I call up Dad to act as a sounding board and he agrees that it *should* work since it’s just tying wires together to power another pump.

After a few more hours of wiring hell, placing the pump in, turning the water back on, having water leak from the pump, taking the pump off and realizing there was some sediment that had rusted onto the pipe that I had to file to get a smooth surface, putting the pump back in, having another leak due to me not tightening it up enough….I flicked the breaker and waited for magic to happen.

It didn’t happen.  There was gurgling sounds from the boiler and I could tell that the water heater was getting heat but not the radiators.

I felt defeat.  What a day.  It was ridiculous.  Here I was trying to get heat for my wife and baby and it just wasn’t working.  Vero suggested we call an HVAC guy.  There really was no other option.

I checked the wiring, I checked everything else.  Everything *should* be working. 

Defeated, I started cleaning out the storage room so the HVAC guy would have a good spot to work in.  Vero came in and chatted with me and out of nowhere, when I was at my lowest point, I hear the click of the circulating pump come on and everything comes to life.  I have no idea why it takes so long to come to life, but it did.  Maybe there was an airlock in the system, maybe it has to reach a certain temperature in the indirect water heater first…I don’t know.

But the thing works now.  I was in shock for a few hours and didn’t realize what I had accomplished until later that evening.

I felt like a golden god!  Yes, I still have an issue where the wiring to the pump is so bulky that I can’t put the cover over it…but I’ll just duct tape the hell out of it.

All in all, I’m happy now, but it was a frustrating day.

Leave a Reply

Your email address will not be published. Required fields are marked *