Adding a second heater

[4JawChuck]

I would run the outlet of your heat pump directly through the gas heater...no valves...straight through. This way if you don't want gas heat you just shut it off and water runs through it, you can live with the added head loss for the piece of mind knowing fresh water is going through the gas heater at all times. This way your gas heater can be kept on automatic and "top up" your pool heat as required when the heat pump can't keep up...much simpler installation to.

Its not wise to leave any heat exchanger with standing water in it, lots of processes occur during that time...chemical and electrical at the molecular/ion level. You either drain it or keep flowing fresh water going through it, thats the rule.

Save your self the plumbing headache and valving costs and just plumb straight through BK, you will be happier if you do.

 

[Ranger987]

bk406, I understand the point about inconsistencies. Ask 3 pool guys the same question and you'll get 4 different answers. Part of this depends on where the information we're passing originates. Many eyes on the same issues will produce many perspectives. I've tried to educate myself & pass on information from the manufacturers, as they have the best experience with testing failed product & finding reasons why the failure occurred. Not trying to pat myself on the back or put anyone else down, but much of this depends on personal experience. I've had more than one customer disconnect the heater & just let it sit all winter - and paid for a new heat exchanger after one or two winters. Flushing the exchanger sounds reasonable, so give it a go. My logic is this... If I give you the best information I can, you can then make an informed decision, rather than just using my opinion which may not be good for you and your pool long term. Good luck!

 

[bk406]

I would run the outlet of your heat pump directly through the gas heater...no valves...straight through. \.

I thought about this too, but the other way around. Run the thru the LP, back thru the HP then out. This way would be purely for convenience on my part. The way the original guy plumb everthing, it would be much easier to do that than the other way around.
And like i said before, if the LP is on, the HP will be off, and vice versa. I dont plan on running them togther. If i were, it would make more sense to plumb straight thru the HP then to the LP.

I wonder what the head loss would be doing it this way. Probably not much more, if any as compared to running a 3 way and a couple more 90's.