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[Range91]

Just got my side arm exchanger hooked up today and with my dishwasher running I got about a 15 minute shower and ran out of hot water. I let tank warm up to 135ish which is what I have elements set to. I shut the breaker off and had dinner loaded dishwasher then jumped in the shower. If this is normal for a side arm then I guess I just wasted a lot of time and money . I am have heard plate type exchangers plug up and so many people have said there side arms work great. I attached some pics if anyone sees anything that could be my problem please let me know.. Thanks

[slimjim]

I would bet you have air trapped in the top of your exchanger, it will need to be vented in order to thermo siphon, nice job otherwise!

[mlappin]

I’m betting Slim is right, on my install I placed a baseboard T where your sidearm comes up then makes a ninety to connect to the top of the water heater where your relief valve is, I then used an auto vent in the baseboard T.

It should work better then you mentioned.

Before my father remarried we had three in the house, and if the wife spaced it, did laundry and dishes then all three of us wanted showers before going somewhere, last person was gonna have a cold one.

[Range91]

Thanks for the quick replies. I will try venting and give it a few more days of use see how it go's. Worse case 10 plate exchanger on cold side I lest should solve my problems correct? Any particular brand of plate exchanger better than others?

[schoppy]

I'm using a 10 plate now but it is in a primary/secondary loop setup that Slim helped with advise on. It gives me unlimited hot water with no problems so far. I am not sure how your sidearm is plumbed in but beware that a 10 plate has a lot of restriction compared to a 20 plate or side arm. My 10 plate DHW exchanger does not have valves to isolate it for flushing it. If it does plug I will be changing it out with a 20 plate and installing valves that will allow me to flush it annually.

The only thing I will need to find out what is recommended for flushing plate exchangers with?   

[RSI]

If you are putting a plate HX in the main loop I would not use a 10 plate. If you have it on a secondary loop or use something like a mono flow tee then it is probably ok.

If in the main loop, a 20 should be fine unless you are already near the max of what your pump can handle. If that is the case, you are better off going with a 30 plate than having to go to a larger pump.

I like GEA plate heat exchangers because they are made in USA and don't cost much more than the chinese ones.

[racnruss]

my last side arm plugged with hard water.  It had numerous small tubes inside a large tube.  That made it better because of increased surface area but it plugged because of small tubes and hard water.

Now I just have a 20 plate on cold side of water heater  and no side arm at all.  Works great.  Plus have a water softener now.

[lindnova]

Is your sidearm top higher than your water heater.  Mine was and wouldn't thermosiphon. 

I eventually put a 20 plate in and am on 100% wood heated water now.

[mlappin]

Is your sidearm top higher than your water heater.  Mine was and wouldn't thermosiphon. 

I eventually put a 20 plate in and am on 100% wood heated water now.

It should still work as long as it isn’t too high.

I believe on Central Boilers diagrams they claim to keep it within four inches of the top of the water heater.

Lower the better though if possible, but sometimes it just ain’t.

[woodbutcher]

I've had a side arm on water heater for 17 years and never ran out of hot water. I heard that if you do run out of hot water, an easy fix would be to install a Taco 006 pump to aid in the circulation to keep your water hot. Taco makes that pump just for that reason. It pumps at a low volume and keeps the water in the water heater moving.