Help on wall hung Combi units

[mfournierr]

My basement has flooded for the 3rd time and my 1945 Weil-McLain boiler 135K BTU has finally had enough. Since they added natural gas to my neighborhood I am switching over.

I have had 2 contractors come and look at my house and one contractor who just gave me a quote. they quoted 3 different units and the prices were far apart. I am more confused now then when I started looking into it.

One contractor quoted me a Bosch Greenstar... The second a Navien Ch/240/NG and the third a Rinnai Q175C. I have a 1100 sq ft house that is older and live in Maine I will be running my heat and hot domestic hot water off this unit only 2 people in the household.

I have looked into all three units and have read bad and good on all of them. I am struggling to pay for this as it is and could use advise on which unit might be the most reliable and best fit for my needs. Or should I just go with a floor model direct vent system? I want to get rid of my chimney..Thank you in advance for any advice..

[Chris_Worthington]

Moved to AOP

[mfournierr]

Thank you chris for moving my thread to the right location and I apologize for posting it in the wrong spot

[motoguy128]

I have a Navien Tankless and really like it. Now issues so far after almost 2 months of use.

The important thing is to get an installer that really knows tankless unit, gas pipe sizing, sizing the water side piping, circulation pump sizes and so forth. Proper set-up of the control setting is improtant too. Its' all in the installation manual and a good regional Navien rep can help. It can be piped just like a HE furnace with regular PVC, no special piping. I think ti can be veted a pretty long distance, around 100' if needed depending on teh number of elbows. If its' a very very short run with 1 or 2 elbows, you can use as small as 1-1/2" pipe. The 2nd pipe for combustion air is optional, but I'd recommend it so you're not drawing in outside air and eliminate backdrafting.

I cannot yet comment on long term reliability. But Navien does use stainless steel heat exchangers and interconnecting piping.

[BaldLoonie]

Are you planning on this machine for heating the home and domestic hot water?

[mfournierr]

I am planning on using this for both my heating and domestic hot water.

[motoguy128]

Are you planning on this machine for heating the home and domestic hot water?


Thats sort of the definition of a Combi isn't it? :grin2: