hodge

We used to have an Apollo system upstairs as well as one in the improved basement. Original housing developer (long since gone under) ripped through the neighborhood apparently installing the units as cost saving measure. Was able to replace the upstairs with a gas unit 5 years ago (can't downstairs) but before upstairs was replaced we used got to get this annoying sound coming from the system whenever it kicked on during the winter. Called an HVAC guy for a service call, he'd never seen an Apollo (about 2009) and said I needed a plumber to checkout the water heater. The plumber came out and said I needed to work with an HVAC guy because the problem was with the Apollo unit. Years later after getting to know the system better, I realized the bearings in the Grundfos pump in the Apollo system had been going bad and sending the noise throughout the system. But your point is a good one and I'll considerin reaching out to HVAC people again. Thanks for the good advice.

Appreciate the response Jim. The plumber "guessing" about the specs was a poor choice of words on my part. The plumber is concerned about selecting the right water heater for hydroheating 1,500sq ft. since he'd never seen an Apollo system until I showed him mine. He did recommend an A O Smith Promax Plus Series 100/101 with side connection based on the Energy Guide yellow sticker from the Apollo heater; which was First Hour rating 98 / 50 65.0NQRT8 5FJ (which I'm guessing is short 50 gal. with 65,000 BTU.)

We have a 1988 Apollo 50/50 heater that needs replacing. System surprisingly continues to work fine, just very old. Plumber I'm working with is very helpful but never installed a replacement for an Apollo. He's guessing a BTU Input: 60000 with the two side taps, 1st hour recovery at 98 gallons, Recovery 90?F Rise: 61 GPH, not Energy Star rated, would be adequate for the 1,500sq ft downstairs improved basement with Earth covering 20% of structure. Could include the model number but I've never used the forum before and don't want to break any rules. Would this heater be sufficient? R value is listed as 16. Any feedback or other choices to pick from (if allowed on forum) would really be appreciated! I also have a brand new heat exchanger (bought overstock years ago) that he'll also be replacing.