Radiant Heating/Hot Water System

rm206

I'm a homeowner who purchased a home with this system already in place.  We've loved it and it's worked well until last weekend with the 2005 Noritz tankless heater kicked off.  We immediately called a tech and he come out and identified some corrosion on the heat exchanges as well as some other issues with the heater.  He however determined he didn't have the knowledge of the system to make the fixes.  I contacted a second company who came out and provided a much more knowledgeable and complete analysis.  They concluded that the heater needed a fair amount of repair and a new one would be recommended.  In addition they noticed that we had an open system, it was pointed out that this could present a water quality issue and they recommended we address this issue as well.  A thorough review was done of the radiant system that lives in the crawl space and it was concluded there was no issue with the radiant piping system. 

We were provided two expensive solutions (especially considering the fact that we like the system and didn't think we had any issues).  The first option is to purchase a Bosch system that has separate tanks built into the heater and to make some changes to the system design to close the radiant loop.  The second option is to purchase a triangle tube and and exchanger and modify the system this way.  Both options came at a cost of nearly 15k.

My question is are either of these options the correct solution?  Should we have other concerns or consider any other issues before moving forward?  Are there any other options, preferably at lower cost?

I've been told that this forum would be the best place to look for answers for my problem.  I appreciate any insight or feedback and can provide additional detail if needed.

Ironman

Open System + Tankless = Bad News

It sounds like you've become yet another victim of the internet radiant peddler.



A tankless water heater is not designed, controlled or approved for space heating. It makes a quick, cheap sell for the internet peddler whose target is only looking at the cheapest equipment cost. I'm surprised it lasted this long.



Open systems are breeding ground for Legionella as well as a host of other problems.



What the second contractor told you sounds essentially correct. There is one other thing that needs to be confirmed: does the system have O2 barrier tubing? If not, you're gonna be limited to using a boiler plus a heat exchanger to isolate the non-barrier tubing from the closed side. You cannot connect non-barrier tubing directly to the boiler or ferrous components. You also need the required ancillary components on the open side.



Discussing pricing is against forum rules, so I can't help you there. You may want to get a couple of more bids from COMPETENT radiant contractors for comparison. I'm not implying that yours is not. Check the "Find a Contractor" tab above or post your location to see if there's someone on here near you.

rm206

Thanks for the help

I appreciate the information and apologize for the pricing gaffe I didn't know that was off limits. I'm in the north Seattle area and anxious to understand more about my options and resolve this issue for me and my family.



If you can help please contact me at noodles2228@yahoo.com

nicholas bonham-carter

Perils of the open system

The water in the heating system , which is connected so thoroughly with the domestic hot water system, can pick up and nurture some deadly bacteria, so that when you have a shower with this same water, you can be inhaling all this legionella (legionnaires disease).

The 2 systems must be separate.

You could add a separate tankless, along with a new boiler, or find a combo unit which provides water for heating, and also Waterford DHW, and keeps them separate.--NBC

Ironman

Paul Polletts

Go to the "Find a Contractor" tab above you'll find Advanced Radiant Technology in Seattle. Contact Paul Polletts there. You won't get any better.



For some reason I couldn't copy and paste it here.

rm206

Very helpful

Your posts have been very helpful and I've tried to contact Advanced Radiant Technology both by phone and email and am having no luck. The contractor page doesn't list anyone else in my area, do you have any contacts to offer?



Thanks again



RM

Ironman

Paul

He's also involved with the Radiant Panel Assoc. doing training. I'd keep trying him. If he can't do your job, he'd know who to recommend in your area.

JHB

try this

split the heat from the DHW an put in a system like the navien. My contractor installed one while we were under construction as a temporary system. It was very simple and worked well.



Seems like it would reproduce what you had with minimal changes.

JHB

oops duplicate!

split the heat from the DHW an put in a system like the navien. My contractor installed one while we were under construction as a temporary system. It was very simple and worked well.



Seems like it would reproduce what you had with minimal changes.