Lochinvar boiler question

Ike Gatlin

Its monday morning... reading posts on installations like this first thing arent good for my heart.
Shrub... why dont you give me a call, I would love to know where this job is.
615-889-8900

Big Shrub

Not a lot of gas in my area. Ran into my first Lochinvar LP boilers in my 30 plus years in the business. Question #1: is a RBL 270 rated to directly heat domestic water (car wash)? City straight in! I haven't ran the figures, but 270,000 btu seems way out of line for 2 washers that use 3 GPM ea at probably not over 120 deg.
Question #2: Lochinvar RBL 180 on radiant heat. I found this one pretty well plugged(off on roll-out switch). I can't believe these things are supposed to work with return temperatures as low as 40 degrees? Someone made a poor attempt at primary / secondary piping, might as well be straight in. After a while, supply temp to floor goes from 40 way up to around 120 - no means of control. Assuming the Lochinvar needs a 120 deg or better return temperature like most other non-condensing boilers, I need to repipe without costing this guy an arm and possibly a leg too. Has anyone had success with thermostatic bypass valves for boiler protection? I'll probably go with variable speed injection to control water temp to floor. Other problem is snow melt, wash bays, and utility room all on the same (only) zone - nine 3/4" loops. I wrote too much. Bigshrub

hr

Most

Lochinvar boilers are listed as boiler and water heaters. I'm not familiar with that number but the manual should tell you or go to their website for a manual on the unit.

That could supply plenty of hot water for the wash if it has some storage capacity. Rare to see water in and out of a DHW boiler without some sort of storage tank? They are not intended to be instantanous DHW sources, typically

As for the snowmelt, fix or repipe the primary loop and use a variable speed injection pump to handle both the mix down temperature, for the melt, and boiler protection from one tekmar control.

No need for a thermostatic return protection if you install and program the VS control properly. It watches return temperature at the boiler piping and adjust the VS accordingly.

Might want to run some load calcs for the area you are trying to snowmelt or de-ice. 180K At @ 153 output, or less with derate, doesn't do a lot of snowmelting if you design around 100 BTUs per square foot.

hot rod

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Dave_12

1. The RB series was a heating boiler (L for LP), a water heater would be a CWL. There aren't many differences, mainly relief valves and controls. Lochinvar's copper tube type heaters are meant to be used with a separate storage tank and cold water should not be put straight into it, we want 140 degree return to it.

2. Again, we want 140 degree return. Hot Rods suggestion is great (of course). We've had good success fitting these boilers with 3 way thermic valves in a Primary-Secondary configuration. I'll try to remember to send that information on monday when I'm in the office.

Big Shrub

Hot Rod - thanks for the advice. I found a manual on Lochinvar's website. The boilers are no longer produced. Ironically it is listed to the left of the regular car wash models. The Tekmar control suggestion is the way to go. I was searching for an easy way out for the owner without a total re-pipe. Guess I'll have to mostly redo it. I'm not tooled to deal with the 3/4 pex. Typical nice guy & he really got screwed. This installation is 2 years old and borders on criminal - especially after I just finished reading the manual. Lochinvar boilers obey the same laws of physics as everyone else. The vents are standard single wall thru the roof and are starting to rust thru from condensate. No sure source of combustion air. Boiler room gas input exceeds 600,000 btu's on a single 3/4" black line with an equiv run of about 50'.

The 270,000 btu DHW boiler is piped instantanous (no storage) against manufacturers reccomendations. The only flow thru it (except for 3 GPM usage from each of two washers) is from the 1/2" return line which has a rather large bronze pump on it. I didn't look at the pump model, but it is big and produces lots of velocity noise.

Seems to me the heating boiler and the DHW boiler could almost be swapped - but he has not had a capacity issue. The outdoor snow melt load is only a small piece of sidewalk. Although I would guess that the 2 wash bays are treated the same as snow melt. He doesn't fire the boiler until he sees ice on the floor. The boiler room overheats and appears to be circuited separetly so I can put it on its own zone.

Last month's LP gas bill was $1200.00 and the gross was $800.00. If I were the owner, I would do my home work and go after the installer. Hopefully a proper install will save him a good 25% or more.

Bigshrub

Big Shrub

Brant - Thanks and feel free to contact me directly if you think it might help (bigshrub@hotmail.com) I can provide phone & cell numbers. Is there a local rep? Zip 16666 I plan on only re-doing this job one time. I think it will have a quick payback. Please read my previous post.

Big Shrub

[Deleted User]

The math...

on the 270 K boiler sez that with 2 points flowing, and a 100 degree F rise, you can get 2.16 GPM of 100 degree F rise water. Sounds about right, but only IF both heads are flowing at the same time. If not, short cycle city...

The configuration, although against common sense, sounds righ in line wiht typical carwash operation. I remember walking into my first car sash mechanical room and saying to myself, This just don't look right.

But after considering the amounts of chemicals they dump, the and pressures they need, "It'll work".

They definately do things differntly on that side of the line...

ME

Rodney Summers

Modulating GB142 with Tekmar 360 &Quick-Mix? (what's needed?)

Have a pre-installed system that's a:

Tekmar 360 (with outdoor reset)
GB142/30
Buderus Quickmix
Superstor Indirect

this supplies three zones downstrea, controlled by zone valves.

What do we need to add to the system do modulate the boiler. In the existing system, the boiler temp is manually controlled (dial on buderus) and set at 150, above the condensing / efficiency range.

Could we add a 270 or something to this system? If so, how would you configure?

thanks