TT Challenger Fittings for Near Boiler piping

try2hard

Hi everyone. My old water heater died today so I decided to hook up the DWH circuit on the TT Challenger. I've had the boiler mounted, gas line installed, and venting completed -- just haven't put it into operation yet. Since the Challenger can act as a standalone DHW heater, I figured I'd go ahead and hook up the DHW lines and fire it up.

However, I'm having an issue with the near boiler piping. Brass compression to NPT fittings were provided but I was going to use Sharkbites for a quick DWH hookup. The DHW lines are 1/2" (or so I thought) and the boiler supply/return are 3/4", both bare copper. My 1/2" to 3/4" Sharkbite coupler slid right off the copper. I tried the fitting on another piece of 1/2" copper I had lying around and it fit securely. Apparently the OD of the copper DWH lines is just slightly smaller than 1/2", but larger than 3/8".

Next I tried the provided brass compression to NPT fittings, thinking the copper might be metric sized?, but they also slide right down the pipe. I have no idea how the provided fittings would work either. The boiler supply and return appear to be standard 3/4" copper as the Sharkbite couplers fit perfectly on those. But even the provided 3/4" compression to 1" NPT still slide off the boiler side.

Sweating is a no-go because it's connected to the boiler internally and states explicitly in the install manual -- no heat sweating to near-boiler piping.

Any ideas or suggestions? I was planning to quickly have hot water since the rest of the boiler is connected and ready for service! LOL

the_donut

Probably a solder fitting you are trying to compression/sharkbite over. See if copper pipe fits in. If threaded, use threaded connection.

Also not a big fan of sharkbite that close to boiler in case something happens with too high temp on dwh circuit. Compression has a tendency to weap with expansion and contraction, and is easy to go gorilla on and over tighten.

kcopp

They are metric but they give you the metric x 3/4" male adapters to adapt to them. They should fit right into the jig bracket.

try2hard

Thanks for the replies.

The provided compression to NPT fittings simply wouldn't work. The ferrule ring has more slack than I've ever seen; I can't imagine it would compress enough to provide a leak free seal. I'm thinking perhaps a mishap at the factory, providing the wrong compression fittings. They do fit correctly over a standard piece of 1/2" copper.

I think I'm going to try a 1/2" copper press fitting, that might be my best bet.

kcopp

I would not do the press fitting...
I would get an assortment of compression fitting from a supply house to figure out what will work. What fittings did you use on the Heating side?

try2hard

I was thinking the copper press fitting would have enough tolerance to handle the <1mm difference in pipe size but maybe not. I wish I had an extra piece of coper the same size to test on.

Thanks for the comments.

hot_rod

Probably 15 and 18 mm, .590 & .708. Those are common Euro sizes.

I've used an expander tool and stretched those sized to fit 1/2 & 3/4, but not if you cannot solder on it.

Dresser couplings will take up that tolerance if you can find one rated for the temperature.

kcopp

I would contact a TT supplier...
That unit has a jig that is supposed to connect to those pipes.
Its not meant for a direct connect.

try2hard

Thanks for the comments. I ended up re-piping it yesterday with Sharkbite slip couplings to standard 1/2" copper -- worked like a charm. The boiler piping is standard 3/4" copper.

@kcopp I first attempted the supplied jig bracket but there was no way the brass ferrules on the supplied compression fittings would have sealed. They fit looser than anything I've seen. And I haven't hooked up the boiler side piping yet. This unit doesn't require the CH side to be connected for DHW, since there are separate coils in the heat exchanger.

try2hard

FYI -- I'm very impressed with the performance of the unit so far. I've never seen a boiler modulate it's firing rate so quickly -- split-second adjustments! I imagine it prevents a lot of short cycling. I can't wait to try out the heating performance this fall. The modulation ratio is about 6.5, which isn't bad for a value-priced unit.

It's also very quiet, much more so than the TT Prestige I installed at my last house. Only a quiet noise from the ECM motor. It was even quiet during high-fire testing.

kcopp

try2hard said:

Thanks for the comments. I ended up re-piping it yesterday with Sharkbite slip couplings to standard 1/2" copper -- worked like a charm. The boiler piping is standard 3/4" copper.

@kcopp I first attempted the supplied jig bracket but there was no way the brass ferrules on the supplied compression fittings would have sealed. They fit looser than anything I've seen. And I haven't hooked up the boiler side piping yet. This unit doesn't require the CH side to be connected for DHW, since there are separate coils in the heat exchanger.

Its a nice piece of equipment.
Its the sister boiler to the IBC HC/ DC unit.
IBC made some changes to the jacket and the way it gets mounted that I prefer... most notably that jig is not needed.
Both are made in the Netherlands by Intergas.
That jig also holds the boiler in place.
Yes the ferrules are a bit wonky but they do tighten up pretty well.
I have 20 or so installed.

the_donut

@kcopp do you treat the condensate downstream?

kcopp

If it goes into a drain yes. In that case it runs outside.

try2hard

@kcopp Just a quick question for you.

My CC125H has been running for DHW only for about a month now. Last night I was inspecting the condensate trap and noticed about 1 teaspoon of off-white powder settled in the bottom of the trap. I emptied the trap and refilled; it was like a very fine sand. Is this normal upon startup of these units?

Everything is working fine and the initial combustion tests were excellent, after the LP conversion, both at low and high fire. I also cleaned the PVC venting during assembly to ensure there was no debris that could make it's way back to the HX.

kcopp

Normal...
Especially if it a new install there will be a bit of sediment in the trap. If the unit condenses more the combustion byproducts will be washed down into the trap. In some extreme cases I have had that get blocked because the homeowners did not have me go back and service the boiler....

try2hard

Great, thanks. Good to know.

I haven't noticed this with the TT Prestige(s) but that has a different burner and HX of course.

the_donut

Condensate may need ph raised to prevent drain from being eaten over time.