tankless hot water unit recommendations?

For 2 showers a larger Takagi or Rinnai are good. It is all about gas supply, water gpm, incomming water temp and temp rise produced, you have to measure everything and not guess. I don`t know your location but incomming water temp lows are most important in your pick, my water goes to 35f and I do fine with a small 117000btu Bosch, actualy I never set the heater on high and get a hot shower, but 2 showers probably needs

185000 btu. Another over looked issue is gas supply, a tankless will likely more than double or tripple what you use so calculating supply with all competing apliances on and gas pipe size is critical if you want your tankless to output its rated Btu, if it doesnt reach it rated btu you can be left cold. You need to measure flow with a manometer.

The payback is there, for me its 4-5 yrs, but if you have a family you can loose money if people get the idea the HW is endless and have endless showers. The greatest payback 25-50% is the single user. Tankless have nothing to rust, should last 30 yrs and don`t loose efficiency every year, as gas tanks do, due to scale. My old tank had

1ft of scale in it so it was probably 50% efficient. If you have the $ takagi makes a condensing 94-96% efficient Propane tankless. Look into the remote thermostat option.

I installed the Paloma 7.4 GPM unit available at Home Depot and am very pleased with the performance. With the energy tax credit and utility rebate I received my actual cost was less than a traditional water heater. What the other guy said about gas flow etc. is all valid and I would add that when in doubt about sizing the unit - go bigger.