With the addition of the new ST series water heaters by Suburban, there are now 3 units in the lineup for the on demand category! The ST-42 is a 42,000 BTU unit and the ST-60 is a 60,000 BTU unit and both come with an included wall mount thermostat. The greatest benefit of the on demand units is that they only pull power when you need it! These units only draw 3 DC amps during operation which is super low! Now you do need to make sure your water pressure is correct but that being the only caveat, these units are a no brainer. Not only do they help with power, but they save space at only 12-3/4 W x 12-1/2 H x 13 D. If your old tanked unit is feeling a bit tired, maybe it's time to go with the on demand upgrade!