Dan's Book Should Be a Blunt Force Weapon

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Hi everyone. This is my first post here, but felt like I should tell my story and why I (hopefully) am glad to have Pumping Away as a lethal force weapon to use with the local Chicagoland HVAC companies.

I had a new NTI modcon direct-vent combi boiler installed to replace an old 80% efficiency (probably more likely running at 65-70% given how crappily it was originally set up) cast iron unit going through my house's flue. My goal was to get rid of the flue requirement so I can eventually yank out my very old chimney, and to better utilize the basement space. The installer achieved that. The hot water works just fine.

However, as I found out shortly thereafter, my radiators now had all kinds of bubbling / cavitation noises going on, especially upstairs. I didn't really know why, so I called the company back out. They refilled the system, upped the static pressure a couple PSI, and left. Of course, the prior, junky cast iron boiler didn't exhibit this problem, probably because it was pumping away from the tank. More on that in a few sentences.

...and, as I'm sure those of you who have read Dan's book can attest, the bubbling noise came back despite the raised pressure. I had to basically educate this company after reading Pumping Away and checking out Dan's site here about how modern hydronics works, and why the fact that they had the B&G pumping into my Amtrol tank, and then into the boiler return, was pulling air out of solution at my top radiators. I had to remind them that both Amtrol and NTI say to put the darn pump after the tank, and in both cases, also after the supply side of the boiler.

Today this installer was back after having agreed to pipe everything the correct way, according to basically all of Europe and Asia, as well as the NTI and Amtrol manuals. Nevertheless, all the installer did was move the spirovent from the return side to the supply side and hike the static pressure to 20psi for my average two story home (!!!). He tried to call it a day, at which point I called the HVAC company and effectively told them that's not what their operations manager actually agreed to do, and why it won't solve this problem. They are finally piping it the correct way. I'm hopeful that Dan is in fact correct (and I'm pretty sure he is) and that my bubbling problems will now go away.

I tell this story as a cautionary tale for anyone who might be running a hydronic heating system. Spend the money on Dan's book. Do some basic research on the Internet. And then ask your HVAC company on any potential install, where will they be piping the tank and pump? If you don't, you might get an installer like I did that says "this is how we've always done it and we don't have problems."

Steamhead

The lesson here is- next time you need a heating company, use this site's Find a Contractor page.

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Here is a fun picture of how this was originally piped.

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Steamhead said:

The lesson here is- next time you need a heating company, use this site's Find a Contractor page.

Indeed. I wish I knew about this page before I hired them. Since they already have my money I want to at least ride out my warranty period and get the correct work done, and then I'll find a new company that knows what it's doing for regular maintenance.

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Here is how it looks after the work. Curious to hear some more expert opinions. It does appear we're not pumping away from the tank.

Obviously he needs to hook the pump back up, but so far the piping looks correct to me. Thoughts?

Tinman

It depends on whether he spun the pump on the volute? On the wall side of the pump, there is a directional arrow. If it's pointing up, he's pumping away.

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Steve Minnich said:

It depends on whether he spun the pump on the volute? On the wall side of the pump, there is a directional arrow. If it's pointing up, he's pumping away.

Yes, it should be pumping away. The B&G pumps left -> right from with the label facing out, and it's on the supply pipe and not the return pipe. Otherwise it would be pumping toward the supply, and we know that probably wouldn't work

STEVEusaPA

All the smartest people are here, and the rest of us are learning from them.

Tom_133

Ok, so that is a combination boiler, and that being the case, it should be piped with the closely spaced tees it was shipped with from NTI, I dont see it, is it there?

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Tom_133 said:

Ok, so that is a combination boiler, and that being the case, it should be piped with the closely spaced tees it was shipped with from NTI, I dont see it, is it there?

Are you talking about the Send / Return T (it really looks more like an H)? It's there at the very bottom of the boiler hooked to the send and return, it's just hard to see in the photo because the gas pipe is in the way.

In any case, I ran my thermostat at max today (despite it being warmer) to give a good, long run the past four hours, and not a single water noise showed up in any of my radiators. They are dead quiet. I don't even remember hearing any knocking when they were getting up to heat. Hopefully that is a good sign!

Tom_133

yeah, if the "copper H" is installed then it should work well for you the way they have it now.