Sidearm not heating water

[rick2752]

Sidearm not heating water. Haven’t completely removed but I don’t think it’s clogged. Anyone sees problem with my install? It’s been hooked up for a few years but I’ve always left propane backup on. Now I’m wondering if it ever worked. It’s not even making the water warm.

 

[NSMaple1]

What's up with that copper pipe at the top going off to the right? Sidearms work best when the domestic water can come out the bottom of your tank straight into the bottom of the HX, and out the top of the HX straight into the top of the tank. That little down loop at the bottom might be affecting things. Maybe.

 

[rick2752]

Small copper pipe is just a return from master bedroom. It essentially does, I took it apart there are no blockages

 

[NSMaple1]

Whoa, hold up. That is a heating return line? So you're mixing heating system water and domestic water?

 

[rick2752]

No not mixing. Top and bottom of sidearm go to domestic. 2 red lines out of sides are boiler.

 

[NSMaple1]

But there's a third copper line, at the top, going to the right in your pic. You said it was a return?

 

[rick2752]

Yes it’s a domestic return the domestic water goes to master bedroom and has a return. It used to have a pump but it was to noisy. It has a shut off valve and I have tried both open and closed to no avail. But it goes into a t that feeds into the top of the sidearm. So it mixes only with the domestic when open. My last sidearm would actually thermosiphon the whole loop and I had almost instant hot water in master bedroom.

 

[NSMaple1]

Ah, ok. Think I got it now. Should be able to feel where heat is or isn't going. I'm kinda thinking there's enough scale buildup inside that heat transfer isnt happening like it should. Might need real good heat transfer to pull the water down around that loop at the bottom. If I still wanted to make this work I might just get a new one, short enough to fit between the ports. Would save the descaling hassles. Or I'd try descaling. More likely to be the dhw side I think. But would do both.