Here's a Puzzle for Everyone, see who can figure it out

[Christian Beebe]

So we have a ten unit complex and have owned it for four years.  It's a great solid building but the main issue has always come down to water usage.  In the last two years, during the same winter months of Nov/dec/jan water bills and "usage" have doubled, EVEN WITH less tenants in the building.  

In our area, we are billing quarterly and here is the breakdown of usage in DCF's per month

2014

Nov - 765

Dec - 1110

Jan (2015) - 1135

2015

Nov - 690

Dec - 1050

Jan -1085

2016

Aug -395

Sept - 355

Oct - 195

Nov - 820

Dec - 985

Jan - 875

and keep in mind for 2016 out of ten units, three were empty from Sept on.

We have gas boiler heat and of course water heaters (two in this building).

In August of 2016 we actually installed water saving devices in every units toilet, shower, sinks, etc.  

We don't have any major leaks because the water meter outside doesn't move or spin after sitting still for minutes at a time.  There is no leak between the meter and the building due to the same thing mentioned above, no spinning meter.  

Now the kicker is we have two other building right next to this one and during the winter months, usage goes down! 

If 1 ccf (which is 10 dcf's) = 748 gallon of water, that means in the three winter months ten units are using 200,000 gallons of water in three months or 6,700 gallons of water per unit per month versus a normal 3000 gallons a month, which is still high for one bedroom units.  

So with no leaks turning the meter, what possibly could be causing the water "usage" to be so high during the winter months only?  There has to be water passing the windmill type water meter in order for it to turn correct?  And this is the radio type meter that is read from the street.  

I just checked the meter myself as today 2/15/17 is the next reading date and it's only showing for the last 35 days 184 dcf's or 18.4 ccf's or 13,400 gallons of water usuage.  And this is for a total of five units being occupied in the last month for 2,600 gallons per unit.  

The boiler is brand new from two years ago and is an 85% efficient boiler and the water heaters are three years old.  There is one coin laundry washing machine.  

Thoughts or ideas?

Thanks,

Christian