Hi Debra, the T-K1 will run two showers at once, but not two tubs. It will fill 100 tubs one after the other though. Now, if you must fill two tubs simultaneously, the 235,000btu T-M1 is what you need. IT will do what you ask. The labour cost to install them is the same as, or should not be more than the cost to install a regular water heater. After it's hung on the wall, it's just two water pipes, a gas line, t&p valve and flue, simple. We have very gracious hosts here, and I like to respect their hospitality by not blatantly advertising or posting prices. I try to limit my responses to answering questions about tankless water heaters. If you are interested in a heater, please e-mail me or call 800 851 9891. Thanks, Brian.