Heatpump bypass????

SuperMiguel

Well-known member
Nov 26, 2017
47
Tampa/FL
I just purchased a hayward heat pump (HP21404t), they recommend on their user guide 2 manual isolation valve (one on the inlet and one on the outlet of the heat pump) also a bypass valve, and a check valve (if you have an automatic chlorinator or salt system, which i do)... My pool builder says that he normally puts the heatpump straight in without any valve not even the check valve.. What is you guys opinion on this? FIY my pump is a 1.85HP
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,553
Laughlin, NV
I have none of those items on a normal gas heater.

I know the check valve is unnecessary. But the bypass is a bit up to you. I would not like old water sitting in the heat exchanger for long periods. But being able to isolate for a problem with the heater may be nice.

Take care.
 

SuperMiguel

Well-known member
Nov 26, 2017
47
Tampa/FL
is that the only time when i would bypass? i thought the bypass was for when the heater is not being used (summer time) you would bypass it for few months..
 

sktn77a

Gold Supporter
May 16, 2010
1,675
Chapel Hill, NC
Any trace of chlorine getting back into the heater (easily identifiable green copper chloride/sulfate residue) will invalidate the warranty. The check valve should prevent that. (If you use a hayward valve, they will not warranty it against chlorine damage, but it's a lot cheaper to replace than a heater!) Like mknauss, however, I don't have one.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,553
Laughlin, NV
Your SWCG creates chlorine. Now, it is not very concentrated and thus is only a couple ppm above what is in your pool.

Up to you on the check valve. It increases TDH so will increase your operating pressure.

Take care.
 

needsajet

TFP Expert
LifeTime Supporter
Jan 4, 2016
4,721
Sydney, NSW, Australia
A single 3-way valve as the tee between main return line and heater will do anything you might want to do.

Installing the heat pump with unions is not a bad idea. An expandable plug can be used in the 2nd union, or you can buy a third union of same type and make a plug, if you expect to ever want to disconnect it, but still be able to run the pool.

Adding a check valve is only needed for an inline chlorinator (puck chlorinator) or if you're injecting liquid chlorine and there's a chance that could inject when there's no flow. That said, if the manual says so, just put one in. In case you ever want to add a flowvis flow meter, make it a Jandy or Pentair check valve.
 

pooldv

TFP Expert
Platinum Supporter
LifeTime Supporter
Moderator Emeritus
Aug 10, 2012
25,412
FL panhandle
I installed my heat pump about a year ago and included a bypass. I do bypass the heater in the summer and winter. And I used unions to be able to re I've the heat pump and/or drain it for winterizing. There are pics of the install in my pool thread, link in sig.
 

Hayward Pool

LifeTime Supporter
In The Industry
Oct 15, 2014
427
Elizabeth
Hi, the check valve is very necessary for tablet feeders but not salt systems. Hayward's and most in the market place that are hooked up correctly do not need the check valve.
 

SuperMiguel

Well-known member
Nov 26, 2017
47
Tampa/FL
I installed my heat pump about a year ago and included a bypass. I do bypass the heater in the summer and winter. And I used unions to be able to re I've the heat pump and/or drain it for winterizing. There are pics of the install in my pool thread, link in sig.
i didnt see a check valve in your pictures... did you do any?
 

flylegacy500

Bronze Supporter
Jan 5, 2017
21
Merritt Island, FL
We have the same heater and the PB also installed it without the protection which they explained wasn't really necessary since it has a titanium heat exchanger. When we showed them the requirement in the installation manual they came back and installed both the bypass and the check valve. We use the bypass occasionally especially when adding calcium chloride to raise the calcium levels. The check valve is handy for us since we inject liquid chlorine downstream of the heater.