Bosch 520 PN LP Therm Tankless Water Heater, Propane

This Bosch 520 replaced my 25 year old Aqua Star at my off grid summer cottage. Installation was straight forward with clear directions. The unit appears to be of high quality construction and is performing flawlessly so far. One caveat: The entire water valve assembly is plastic and one can only hope it will not oxidize over time and become brittle. Being off grid the Bosch is one of three appliances (the other two are stove and refrigerator) being run off 20# propane cylinders. Normal single person use a tank of propane lasts about 5 days running the three appliances. My experience with propane on demand water heaters is extensive and the Bosch 520 PN LP was clearly the best choice for my application.

I purchased this only to replace the exact one that I installed 3 years ago in my remote cabin which already broke down..It is unreliable and poorly constructed..

We have a cabin in a remote area of Arizona. We had an older model Bosch 1600 PLP which worked like a charm until last winter when we didn't get all the water out and a part froze and cracked. Found out it wasn't made anymore and this model was the closest replacement. We had it installed and it fix perfectly where the old one was located. When we attempted to use it, the igniter flame continued to go out about every 20 minutes. When it went to full flame to heat water on demand it would also go out. Had the installer come back out and take a look. He observed that the possible problem were "loose wires on the upper limit switches that regulate safety". He double-checked the wiring and so far so good. The people at the toll-free number were contacted and notified of this problem. Don't know if it was caused during manufacturing or shipping.

We hooked it up and did not work tried to return but Globale town sent us to Bosch and they only wanted to charge us more. I would not buy anything from global town again!

When my old Aquastar froze during a nasty cold spell I found out that most new models were going to require electricity and plumbing changes, expensive changes for expensive heaters. I called Bosch and they told me this unit would bolt in and perform just like my old one. When I got the new one I laid the two units side by side without the covers on. Except for the Controls they were identical. That's a good thing, all the Aquastar owners I've known are pleased with their product and I'm the first one to replace a Bosch water heater. Highly recommended for what it's designed for; a small house with one demand at a time.

We like simplicity, and this water heater is it. We had one that needed to replace the main copper water heat manifold, and that was very easy to do. That was after 10 years of acidic water from our well. this new one should last even longer as we have filters on our well water now.

Actually Sarah's husband. Water heater is ok and sold as replacement unit for old aqua star 125 I believe. One word of caution; alot of the units in the past used an AQ1 power vent. This one calls for an AQ4 which the kit is like $400. Here is the difference. The old AQ1 which my aquastar used had a line and diaphragm switch off the burner manifold that causes the fan to come on. Good ole bosch does not extend burner out far enough and have eliminated the fitting hole where your old power vent would hookup. They want to sell you a new power vent which uses a couple of different lines and a water flow sensor to kick power vent on. Of course I couldn't just find parts and they wanted to sell you the whole kit. So just look up on amazon a water flow switch (excell company 2L-20L/min) and mount in incoming cold line feeding the water heater. Throw away old diaphragm switch and the 2 wires from your power vent that went to the old switch can be wired right into the water flow switch. The switch I mentioned is like $10-15 on amazon. You know if bosch is gonna sell a replacement and they have changed it mention the changes with venting. Also if u go direct to global towne u can get it for like $999 with free shipping. Don't know why amazon thinks they have to make so much? Doug Swain DVM

This replaced my old tankless that I had about 17 -18 years. The mount and hookup was close but not exactly the same. It is working as expected.

I installed this water heater in an exterior housing unit at my cottage over a year ago and to date it has been fantastic. The heater is able to heat up the water quickly even when the lake water is just above 0 degrees. I highly recommend this unit.On a side note, Bosch is not overly quick to respond on a customer service front. I contacted them as I had a question about installing the unit and it look them at least a week to respond.

Excellent water heater ,installation went really well and it works great.