Gas Instantanious Heater Venting:

icesailor

Does any manufacturer allow venting a non-condensing instantaneous water heater (like a Noritz) into a new, ceramic lined chimney? I don't see where you can't but I can't see where you can.

I have an application that was not well thought out. There is a 30 gallon gas (LP) tank type water heater venting into a block and tile chimney that was installed when the building was built in 2007. The gas water heater feeds a steam boiler for hot make up water. The regular water is fed with a 50 gallon electric. The complaint was low hot water. The top thermostat was bad. They claimed that they didn't use a lot of hot water. I found a Honeywell AMD-1 mixer with no checks. I fixed all that. Now they have hot water but they run out of hot water. The chimney is on the other side of a concrete block wall. The water heater is on the other side. That directly vents into the tiled chimney. You can't go in any direction without running into a problem. The closest vertical outside wall is on a wall/room with hay storage. Vertically, you would be running parallel to the chimney and vent directly below on a plywood and metal roof. Is it ever allowed to use the Stainless Steel vent for the appliance to vent into a lined chimney?

The electric is on a floor above the gas water heater and the chimney. With the wood.metal roof above.

Running inside the chimney with SS flue pipe is not really practical as you need to stage the roof and remove a granite rain cap.

The owner doesn't like the thought of wasting a new chimney.

They're never easy for me.

Exhausting(sidewall) is only possible to the West where the air is salt ladem, year around and there is a 2007 gas furnace where the burners are shot and the exhause is aall black in the PVC from having salty, wet air for the intake.

What say?

CMadatMe

Category III

For A Noritz NR98SV you might. Venting would have to be catergoy III, 4" and no exceed the 39' limit. Would have a drain tee to catch condensate.



http://support.noritz.com/product-info.php?selected_model=NR98-SV-NG

icesailor

Venting:

I can do all that. The vent length into the chimney flue is less that 3'. The 30 gallon gas heater is venting into that chimney. I would be removing that heater.

The question is, can I terminate the SS vent when I go into the chimney. It's staging the roof to remove the granite rain cap that is the problem.

CMadatMe

I'd Say No

You would have to line it all the way to the top. Flue gases are going to condense and your going to need to catch condensate.

Jack

If you check the tables

...which I'm still lacking, I think you will find that it takes many 100kbtu to run a masonry chimney. You don't post the size of the flue. Net/net masonry chimneys are an excellent architectural device, but a poor mechanical device. Honestly, I don't know why people continue to pay for eleventh century technology to be built.



If you cannot give them capacity on the masonry flue or side wall, you may need to look at other locations. I had really good results putting tankless in areas other than the mechanical room. Put it in a closet closest to the point of use. You may have a ball running the new gas line, but it may, depending upon location provide better comfort. Take a walk around the place and see if there are any other options.



He wasted his money on that chimney the day the house was built.

icesailor

Venting Chimneys:

This is a fix-it. Its not a residence. I had nothing to do with any of the origonal installations. The building is less than 10 years old. It is a masonry (concrete block) building. The chimney is on an inside block wall. The things that are in the way are overwhelming.

I know all about chimneys.

This is what gets me. I have a 30 gallon, atmospheric tank type gas water heater (36,000 BTU input) venting into a masonry chimney that is 6 years old. Concrete blocks with a clay liner. All approved with a gas and plumbing inspection sticker. But you can't install a 400,000 BTU, non condensing gas water heater in a clay lined new chimney. If I COULD put a condensing direct vent heater in, the atmospheric chlorides will wreck it in three years.Even the manufacturers don't recomment using their heaters in an application like this. The non-condensing heaters are all power vented and don't need to overcome any resistance.