Indirect water heater vs. DHW coil?

I've had my LL WL-110 for 5-6 years now and couldn't be happier with it. When I installed the boiler I kept my indirect water heater setup, previous boiler didn't have a DHW coil. I'm having issues with the aquastat on the indirect and the new aquastat sensor won't fit in the existing dry well. So this has me thinking do I bother with a new dry well (cheap) or do I upgrade to a 5 GPM coil and ditch the indirect? Anyone have experience changing a dry well, can I do it "wet" with a quick removal and replace or do i need to drain the tank? If I go the coil route who has the best price on the 5 GPM coils? Thanks!

Either way, you have to drain one or the other. It's a big job to drain the boiler. It's a big job to drain the indirect. The coil is $275 and the well is $20. Bust a stud on the boiler and the job gets bigger. How about another new sensor?

you could swap out the well from the indirect without draining tank by " changing on the fly" as you put it Some of the fittings from manufactures are really tight so be prepared with proper length wrenches and cheater bars. Some times the fitting are recessed in the jackets so hopefully they have a hex head. requiring appropriate socket
1.Isolateshut off cold domestic water pressure and
2. valve off domestic hot water at tank if available if not just be sure ALL fixtures valves in house are closed and left closed and not tampered with
3 drain off water in indirect tank from bottom of tank( should be done annually)also)until it stops flowing, which would be in short order less than a quart if you are isolated properly. shut drain valve .
4 attempted to remove the well and have new well taped and doped and ready to go be sure threads of new well are not damaged by visual exam and try a female fitting of same size prior to tape and dope
5remove old well , you may get some burping of water but less than a gallon quick install new fitting
5 tighten water tight.
if a lot of water comes you have not pulled a vacuum by draining or because some valves are not closed and atmospheric air is entering the system find out where

Rob R. wrote: ↑

Fri. Jan. 24, 2020 6:29 pm

Cost aside, I don't think the WL110 has enough grunt to provide adequate DHW output via a coil.

x2.

Mike

If there is even a chance the WL110 won't provide enough DHW it doesn't make sense to change something that works. Thanks for the replies!

I had indirect at my last place and have a DHW coil at the new. I'll be changing it as soon as possible.

The best way I have found to get the well out is impact socket and impact. Normally it will back right out.

Billy2336 wrote: ↑

Wed. Jan. 29, 2020 8:19 pm

I had indirect at my last place and have a DHW coil at the new. I'll be changing it as soon as possible.

What is the rated output capacity of the boiler with the coil?

Mike

It is rated at 5 gmp

To clarify, I was referring to the btu output capacity of the boiler, not the flow rate capacity of the coil.

Mike

It’s a 175,000 oil boiler. The coil may not be as I think, just the way the previous owner had it installed with a 40 gal storage tank.

A 175k boiler should easily be able to produce 4-5 gpm of DHW in real time, which is plenty for many households (esp. if low-flow showerheads are used). Do you have DHW needs greater than that?

Mike

I have no problem with the hot water, it just makes the boiler cycle more than it should, due to how it’s plumbed to a 40gal storage tank. I’m just trying to reduce the amount of oil used.

If the coil output is sufficient to handle your DHW needs you would use less oil if you took the tank out of the loop and just ran off the coil.

Mike