can i use tankless water heaters in line with a current boiler to maximize hot water output?

Question

I live in a 30 unit building with a prehistoric boiler and we always run out of hot water (doesnt matter what time of day or night) does it make sense to connect a tankless water heater before or after the boiler to better stabilize the hot water availability? does it maybe even make sence to have one before and one after the boiler? The buildings heat is also provided by the current boiler...

Answer 1

If I was you, this is what you want to do, disconnect old Hot water line and install new tankless heater directly to the hot water line going to point of use. No need to install before and after, waste of time and money. But I think you should contact the mfg. of some tankless heaters and get their ideas also. Good luck.

Answer 2

Rennai heaters run an array of four or more separate tankless units that cycle from one heater to another under load. When demand is high, additional heaters will supply water in parallel to meet demand.

You can plumb the tankless heaters to supply domestic hot water, and the boiler can be dedicated to heating the building. The warranty on tankless heaters is cut in half if they are used for recycled water on heating systems.

Contact a reliable HVAC / plumbing company in your area for specifics.

Answer 3

You can put these in line with a boiler. They often put multiple tankless heaters in line to get the gallons per minute up. I would think this would be more efficient anyway. Tankless water heater only heat as much as they need to. If the water is already warm, you shouldn't have to put much in to keep up with your demand. If you put one of these in, really watch the venting specifications.

Answer 4

Dont do it. They require a separate wiring, because the pull a lot more amperage and you can burn something up. More at
http://appliancequickfix.com/
Get a bigger heater if you need one.