Plumbing in a hybrid hot water

[bobs64ford352]

Hey all,  I'm getting ready to install a hybrid hot water heater, but instead of having it stand alone I wanted to put it inline with my boiler system.   Currently my hot water is supplied by a oil fired boiler feeding a ~30gal storage tank.  Having already been given grief at work about splash and go showers I'm not interested in others shower routines.  Personally I run hot showers with a drilled out shower head for maximum flow.  This results in some showers finishing up with lukewarm water, but water that never goes truly cold because the oil boiler is able to keep up just enough.  The new water heater is a 50gal and being electric I'm not sure if it will keep up, especially with 4 people in the house.  My thoughts are to tie in the new heater to the domestic inlet of the ~33 gal storage tank, which in my mind should keep the boiler off, but if the hybrid heater can't keep up the temp in the storage will get low enough the boiler would kick on.  I would probably have to install check valves where proper, but just wanted to see if I'm on the right track here or if someone has a better idea for what I have in mind.  Maybe I'm just crazy.

Thanks, Bob

[Diyhound]

I don’t see why it wouldn’t work but personally I’d pull a plumbing permit, have it inspected, and get an official record it meets code. I try to anticipate insurance company claim as well as resale problems.

[jteneyck]

Why not go with a larger hot water heater and forgo the gymnastics?  Or get an on-demand one and have unlimited hot water.  

John

[bobs64ford352]

Why not go with a larger hot water heater and forgo the gymnastics?  Or get an on-demand one and have unlimited hot water.  

John

Mainly cost; I bought the hybrid hot water heater when I bought my heat pump for the house.  They had a deal where the 50gal was $400 out the door and the bigger ones were more than double that for not much more capacity.  I had thought about an on demand for quite awhile, but the best way to go with that is natural gas and I don't have easy access to that.  Another reason I decided to go with the heat pump hot water heater was moisture removal and I need that in my basement.
I reduced most of my oil costs last winter with the heat pump, which met 99.9% of my needs all winter.  I'd have to check all my slips, but I was probably spending upwards of $500 a month on oil and went down to $150 a month extra on my power bill with the heat pump.  The oil boiler came on twice, that I know about, the whole winter for heating.  The first I'm assuming was a long defrost cycle on the HP and the other was during a power outage and I didn't want to run the HP off the generator.  Right now where I'm at is the boiler just running for hot water and if I can cut that by 75% I'd be very happy.  At that I could probably get several years or more out of one tank of oil, as I can get nearly a year right now with it just running for hot water.

Thanks for the input, Bob

[jteneyck]

Wow, that's a huge savings on your oil bill.  I see now why you want to tie the boiler to your hot water heater.  

John

[Cabinet Monkey]

What is the generator you mentioned running off of ?

[bobs64ford352]

What is the generator you mentioned running off of ?

It's a Yamaha 5500 watt, I've had issues with certain appliances not running normal off of it and I just wanted to play it safe with the new HP.  It just so happens I have a 15000 watt generator with ~5% THD showing up tomorrow, so I shouldn't have any issues in the future.

[Cabinet Monkey]

It's a Yamaha 5500 watt, I've had issues with certain appliances not running normal off of it and I just wanted to play it safe with the new HP.  It just so happens I have a 15000 watt generator with ~5% THD showing up tomorrow, so I shouldn't have any issues in the future.

Are these powered by gasoline or propane ?

[blackhat]

Your plan is feasible. I would add a recirc pump pulling from the furthest frequent use fixture and take it back to the inlet side of the hybrid. That will help keep the indirect tank hot without the boiler running. Also insulate all the hot water and recirc piping.

[bobs64ford352]

Your plan is feasible. I would add a recirc pump pulling from the furthest frequent use fixture and take it back to the inlet side of the hybrid. That will help keep the indirect tank hot without the boiler running. Also insulate all the hot water and recirc piping.

I'm glad to hear I'm not off in left field here; I will keep that in mind with the recirc pump.  I'm with you on the insulation, the previous owner never insulated any of the pipes, which took me a couple years to address and I couldn't believe the difference once I did.