Has BW Combi-Cor been fixed?

hot_rod

getting into the heating side the 30Lb relief should trip.
Also that HX tube had a leak detection path to the outside of the tank. A coil leak should show up there first as it follows the plastic leak path to the upper nipple.

They could, and did perform with a typical 15-42 sized circ, just not to the upper limits on the output chart.

Actually even with a high head circ I don't think they ever lived up to that output table on the heating side :)

A fairly unique idea, however. i think you can buy it under the Lochinvar brand also.

BW makes small tanks for lochinvar, and Loch makes large tanks for BW. I think Lochinvar has the largest tank oven??

hot rod

Mark_112

Has Bradford-White's Combi-Cor been fixed?

I live in a townhouse development with in-floor heating driven by a BW Combi-Cor water heater manufactured in 1999, installed in 2001. A plumber doing some maintenance work noticed that our heater was allowing the potable and radiant-heating water to mix. The giveaway was that the pressure in the heating loop matched the potable water at nearly 50psi, and after bleeding water from the heating loop, it would immediately repressurize.

We checked our neighbors and found another failed unit. This makes **three** Combi-Cor failures of this type in our 6-unit development since the units were built in 2001. Our units are still under their 10-year warranty, but after reading a bunch of posts here about Combi-Cor failures, we are trying to decide whether we want to give up and replace the units with a different design out of our own pockets.

I called Bradford-White this morning and got a technical rep. He claimed not to know of any problems with the Combi-Cor line, and pointed out that under warranty, we would receive one of the newer Combi-Cor2 models with a redesigned heat exchanger.

My question to the community here is, does anyone have experience with the newer Combi-Cor2 units vs the older Combi-Cor design? Has the reliability gotten any better?

Also, can anyone speak to the health dangers of using this unit in its current state?

hot_rod

much better now

yes, the older composite coil types had some issues. BW did stand behind every one that went bad that i was involved in. To their credit.

The new version, seen here has a larger glass coated steel coil. Pressure drop and HX with the new coil is much, improved.

hot rod

Mark_112

Thank you, and...

Thanks very much for the reply; this is reassuring. We are mainly hoping to avoid the outright failure of the isolation between the heating loop and the potable water. I'm curious; what is the "pressure drop" problem on the older design that you're referring to?

Rob Blair

In the old units...

the heat exchanger was a 5/8" coil and needed a high head pump to run the heating side.

One question about your apartments is, why would the heating side be able to reach 50 lbs. when it should have a 30 lb. pressure relief on it?

Rob

Steve Garson_2

Mark:

I too have a Combicore that I just replaced in July, installed in 2001. BW paid for the replacement heater. I didn't realize that my potable water was mixing with the heating water until we removed the heater.

The cost difference for an alternative boiler is quite costly, unless your gas consumption is high enough to offer an ROI from using a ModCon boiler. Makes sense only if you plan on staying in your home for ten years or more.

Mark_112

No relief!

Rob, thank you for the feedback. If we put in the new CombiCor unit, should we replace the circulation pump with a lower-head one?

As for the 30psi relief, the short answer is that there isn't one. The plumber who noticed the problem noticed the absence of a release, as well.

My neighbor whose heater has also failed also has a leaking radiant-heat manifold, and we are assuming that the high pressure in his heating loop may be to blame. He's pretty upset. The plumber who was here the other day wasn't able to find the code reference for the 30psi relief on the spot in his truck, but if anyone knows the WA state code section with this requirement, I would love to have it for discussion with the original installers!

Mark_112

Why replace?

Hi Steve,

If you don't mind me being curious, what made you replace your CombiCor unit after 7 years if you hadn't noticed its internal failure?

Steve Garson_2

Good question. My circulator failed and when it was removed, it was completely rusted solid. The expansion tank was full and the diaphram failed. It was obvious that air was in the heating lines, which came from the potable water getting into the heating loop. So with the history of these failures, the plumber replaced it under warranty.

Rob Blair

Yes you should.

It will save you electricity and will not wear on the piping as much. A competent heating contractor should be able to take care of this.

Rob

Mark_112

What should have been installed?

I wouldn't put it past the original installers to have used an inadequate pump; it has always taken a long time for our system to heat up a cold house.

What head pressure would you have chosen for the original Combi-Cor unit, so I can sanity check what's already there?

Thank you very much for your insight.