? for Hydronicsman

[Dof3]

Have you ever used an on demand water heater for infloor heat. Like the Bosch 38B. I used to use a 45000 Lochinvar copper boiler but, they quit making the one I used. The apps I need them for could be done with a water heater but, that isn't very eff. Let me know what you think!!! Thanks.

[Dof3]

Anybody out there?

[condenseddave]

I know that some states have banned the use of water heaters for infloor heating.

There are some very good condensing boilers, such as Munchkin, Viessman, the Weil-McLain Ultras, etc. that fit this bill nicely.

I'm pretty certain that it's Mass. that has banned the use of water heaters, but I could be wrong.

Have you checked out http://www.heatinghelp.com ? (The Wall)there are a lot of radiant guys there that could definitely answer your question about the on-demand heaters, and the legalities and pros/cons of using them in this app. I take it that these are real small radiant loops?

[Dof3]

dave, I have asked on heatinghelp but no responses several times. I use the Munchkin boilers in houses and bigger projects. I was looking for something a little less costly. In basement infloor jobs it is hard to sell a $2000 boiler. I use water heaters because they are inexpensive and easy to install. I think I got about 40 of them working right now. I have about a dozen Lochinvar 45's out there. I like the Bosch 38 because the btu rating is about right and they are relativly cheap to buy. I have not used one for infloor projects though. I have a number of basement floors roughed in with Wirsbo and hope to find a suitable heating plant for them. Thanks for your thoughts!!

[Collin]

We are using this on an island in-floor job.
http://www.takagi-usa.com/web2003/e02.htm

[tinman]

Here in michigan if a water heater is approved by the manufacturer for space heating the code allows it. Rinnai is the only one that comes to mind. It can be used as a stand alone heat source or heat and hot water supply with a heat exchanger. The other brands are probably the same but rinnai is the one I'm familar with.

[flange]

sometimes when you use those types of hot water heaters, you can achieve better results by adding a buffer tank. on small loads, they tend to overfire and cycle too much.

[cmp2k]

Originally posted by Dof3
Have you ever used an on demand water heater for infloor heat. Like the Bosch 38B. I used to use a 45000 Lochinvar copper boiler but, they quit making the one I used. The apps I need them for could be done with a water heater but, that isn't very eff. Let me know what you think!!! Thanks.

Lochinvar still makes the 45000 Btu/Hr model you used previously. However, they have made this product much better. Previously the Mini-Fin (RB Models), this product has been replaced with the Solution (CB Models). These new models are offered from 45,000-260,000 Btu/Hr. check it out at:
http://www.lochinvar.com/product.asp...d=CB045&ln=RSB

All standard on this product now:
-lo/hi/lo temperature control
-built-in performance loop
-top water connections
-2 stage electronic ignition
-built-in draft diverter

[fat eddy]

Look into a peerless Pinacle, Modulating burner,condensing lightwieght quiet and seem to be holding up pretty good, about 2,000 for a 140,000.

[1manband]

I spent two weeks last year rewiring and replumbing three "on demand" units in a 24,000 sq/ft. home. The "plumber" that installed the job allowed for no storage in the system. The "boilers" cycled every 30 seconds and would not heat the house nor domestic hot water. A lot of control rewiring and some added storage capacity the system works allright. I would never recommend an on demand system for heating unless it was 100% modulating, with storage capacity.