Lochinvar WHB199

PFournier

Good evening all. I'm new here so I apoligize if there's a different title I should have posted under.  

I am located in Rhode Island, I have a Lochinvar WHB 199 that was installed in October of 2019 when I was building my house. 

I have 5 total zones though i don't use 3 which is what brings me here.  2 zones are for hot water coils in 2 separate air handlers, 1 is garage radiant, 1 is unfinished basement radiant and 1 is under bathroom tile floor radiant.

House is new construction, R21 walls, R 38 attic, efficient windows. Just under 1900 square feet of heating space for the 2 hydro air units.  

I seem to be using approximately 6 gallons of propane a day for heating the 1900 square feet and making my DHW via the heat exchanger to 40 gallon storage tank.  Does this seem normal for a 95% efficient boiler? 
I had a friend who does commissioning come over for start up when it was installed, he changed a few set points and did a combustion analysis but it just seems to blow through propane super fast. If I run the garage radiant (24x24 3 loops set to 110 via mixing valve) my propane consumption damn near doubles so I don't bother running it.  

Any insight would be appreciated, if I'm over thinking this or missingsomething, I'm open to ideas and suggestions. 

Thanks 
-Peter

pedmec

your confusing efficiency and consumption. they are two separate issues. your boiler will by design be pretty efficient if set up properly. your consumption will depend on a lot of factors. some you can see, like windows open. and some you won't. like improper radiant floor insulation.

how many people live in the house that are taking daily showers and how long are these showers?

can you isolate each zone. its possible to have a leak in the radiant tubing or hydrocoil. shutdown the water feed off and see if you lose pressure in the boiler. i you do then you can isolate each zone until you find the leaking one.

for my money if you have kids i would guess long showers. based on your 6 gallon a day usage (around 550k btus) it really doesn't seem like a lot if you have a high shower usage. check your water meter usage. might be able to get a rough gauge.

PFournier

Pedmec thanks for the reply. I assumed an efficient unit would consume less, so I mistakenly used the term interchangeably. All the radiant zones aren't being used. I have line voltage zone valves on each zone because at one point the system pump was pushing through all the taco 007 circ pumps whenever any zone called for heat.  All radiant has r10 insulation under the slab before the pour. 

There are 5 of us total in the house. Myself, wife, and 3 young kids.  Oldest is 7. No one takes excessively long showers, the little.kids are still in the bath tub. My DHW set point is 140 degrees, with a mixing valve taking it down to 122, so I'm not drawing 100% from the storage tank when there is a DHW demand. 

I will try your idea opening all zone valves and seeing if pressure drops anywhere. Then isolate 1 by 1. I'm on well water so I don't have a way to monitor water usage. 

hot_rod

Running high temperatures above 150F or so you will be getting around 87% fuel efficiency 

Around 91,000 btu per gallon, so maybe delivering 475,000 to the load 

Is the 6 gallon per day at design condition, the coldest day?

Does the boiler short cycle, that can effect fuel consumption. I think you can derate the heating side if the  boiler 

1900 sq feet of home? If so I’d expect the load to be under 50,000 at design. A load calc would help get you required btu/ hr requirement

Could be the boiler us 4 times the size you need?  Read through your manual and see what functions could be adjusted to match the boiler to the load best. 

PFournier

Bob, the 6 gallons is pretty average throughout winter. I messed with some points at 1 point to bring the boiler loop up to 180, its on a ramp delay. I'll have to read more into the manual.  I can talk to the gentleman who designed the system and see what he figured. 

I'm assuming he calculated it to run the 1900 sg ft of basement radiant and the 24x24 garage radiant as well as the finished living space right now. But when I've run those extra zones in the unfinished basement and garage I use even more propane so I'm not sure what the solution is. I'm hoping it's something in programming with setpoints. 

kcopp

Does seem high... How well sealed is the home. Only way to really tell is run a blower door test. that will use a fan to pressurized the home and find the air leaks.
On the garage slab... how much insulation & what type in the floor and walls?

GGross

PFournier said:

Bob, the 6 gallons is pretty average throughout winter. I messed with some points at 1 point to bring the boiler loop up to 180, its on a ramp delay. I'll have to read more into the manual.  I can talk to the gentleman who designed the system and see what he figured. 

I'm assuming he calculated it to run the 1900 sg ft of basement radiant and the 24x24 garage radiant as well as the finished living space right now. But when I've run those extra zones in the unfinished basement and garage I use even more propane so I'm not sure what the solution is. I'm hoping it's something in programming with setpoints. 

Higher output temp from the boiler will lower overall efficiency on that boiler.

To your second point, of course heating more space will use more fuel,

PFournier

Kcopp the home is pretty well sealed. I don't remember the exact number from blower door test.  

Garage slab has r10 under slab, r19 walls and r30 ceiling.  Doors are r16 if I remember correctly.  

HomerJSmith

The boiler would modulate down to 15-20% based upon the demand for heat. I would check your programing. Access to the installer's programing is by typing in 5309. The service manual gives you the parameters. Call lochinvar Tech for any help.