Figuring Out Proper Settings

Z10396 · Post by **Z10396** » Tue. Oct. 14, 2014 7:13 pm

Trying to figure out optimal settings for my WL110. I left everything as is at start up but want to make adjustments to my dhw. I wanted a little bit more hot water so I opened up my mixing valve. Before I adjusted that, I had consistent hotwater but just a little cooler than preferred. Since I adjusted the the mixing valve, I get some hotter water in the beginning of us but it doesn't keep up with the demand at all. Do I need to adjust the L7224 aquastat to help the boiler support what I am looking for from the dhw?

McGiever · Post by **McGiever** » Tue. Oct. 14, 2014 8:07 pm

Tell us what model mixing valve you have...now days for safety reasons 120*F is max. output temp. you can get.

Are you sure you are turning it up and not down???

lsayre · Post by **lsayre** » Tue. Oct. 14, 2014 8:14 pm

McGiever wrote:Tell us what model mixing valve you have...now days for safety reasons 120*F is max. output temp. you can get.

Are you sure you are turning it up and not down???

120 degrees isn't too bad. That's what I've measured mine at as delivered into the kitchen sink. The average shower is taken at only 105 degrees. 120 can still scald you.

Z10396 · Post by **Z10396** » Tue. Oct. 14, 2014 10:38 pm

McGiever wrote:Tell us what model mixing valve you have...now days for safety reasons 120*F is max. output temp. you can get.

Are you sure you are turning it up and not down???

Using Watts 3/4" MMV. Yep, I am sure I am turning it up. Its like the boiler can't keep up.

McGiever · Post by **McGiever** » Wed. Oct. 15, 2014 7:44 am

What are settings on L7224?

Can you post pics of valve w/ piping?

Not that it should matter, but are you burning coal or oil?

Z10396 · Post by **Z10396** » Wed. Oct. 15, 2014 9:16 am

McGiever wrote:What are settings on L7224?

Can you post pics of valve w/ piping?

Not that it should matter, but are you burning coal or oil?

I think it's 190 hi limit 140 low limit. I can send a pic, it's plumbed in the proper way...hot and cold wise. I'm still setup on oil.

McGiever · Post by **McGiever** » Wed. Oct. 15, 2014 12:01 pm

Okay, how about this...I have the same mix valve and mine has screens on both hot and cold inlets, maybe your inlet screen(s) are part clogged.

During plumbing work sometimes too much debris gets in, like solder bits, paste globs and teflon tape strands.

Watts MMV-M1 and LFMMV-M1 Troubleshooting Guide

Problem & Cause
Answer

A. Unable to reach required set point or set point difficult to set
A.1 Supply temperatures not within specified limits A.1 Check differential temperature between hot and cold supplies and
outlet 10°F (5.6°C) minimum required
A.2 Hot and cold supplies reversed A.2 Reinstall valve with supplies connected to marked inlets
A.3 Filters are blocked by debris A.3 Clean filters
B. Unable to achieve required flow
B.1 Too much pressure drop at fixture B.1 Measure supply pressures and check against flow chart. Look for
restrictions in valve or piping
B.2 Checks valve/filters blocked by debris B.2 Clean check valves/filters

C. Valve does not maintain required temperature or temperature
changes over time
C.1 Fluctuation in supply pressures
C.1 Stabilize water pressures with pressure regulating or
balancing valves
C.2 Check valve/filters blocked by debris C.2
Clean check valves/filters
C.3 Recirculation loop not piped properly
C.3 Pipe recirculated tempered water return so it connects
to hot water source and cold side of Tempering valve
(see Product Guide for piping details)
D. Discharge temperature too hot or cold
D.1 Valve not calibrated properly
E. Hot water from cold water tap or cold from hot
E.1 Check valves fouled
F. Valve is noisy
F.1 Water velocity is too high
F.2 Valve not sized properly
G. No flow from valve
G.1 Hot or cold water supply failure or shutoffs closed
G.2 Check valve/filters blocked by debris
H. Flow from valve fluctuates
H.1 Fluctuation in supply pressures
H.2 Check valve/filters blocked by debris
D.1 Readjust valve temperature per installation instructions
E.1 Clean check valves/filters
F.1 Reduce water velocity with pressure regulating valves
F.2 Check flow required versus rated flow capacity of valve
G.1 Open shutoffs or restore hot and cold supply
G.2 Clean check valves and filters
H.1 Stabilize water pressure with pressure regulating valves
H.2 Clean check valves and filters

lsayre · Post by **lsayre** » Wed. Oct. 15, 2014 1:09 pm

My mixing valve fails to deliver 120 degree hot water when the boiler temperature goes below about 160 degrees.

jeff216410 · Post by **jeff216410** » Wed. Oct. 15, 2014 1:21 pm

Is the Low Limit really 140? Also check the third parameter in the boiler aquistat which is the delta temperature. It can be 10-25F if I remember. If it is 10, then the boiler will not crank up the fire until 140-10=130 which by that point you are already going to fall below the 120F output. Try raising your Low Limit to 160 and check the next parameter in the display which is the delta; and set it to 10. This way 160-10=150 at which your boiler will be firing up and you will have some margin to allow the boiler to ramp up heat before getting down to the 130 range. I run LL170, HL 190 Delta 10. This allows me to fill a bathtub for the little ones because the boiler temp starts north of 170 and gives a lot of hot water in a short time but it pulls the boiler down to 120F. I've run 180F LL with a reduced fire in summer to have enough heat stored in the boiler for a sudden high demand, while not having a full coal bed so it does not hit the dump zone.

Z10396 · Post by **Z10396** » Fri. Oct. 17, 2014 2:06 pm

Thanks Jeff, I adjusted per your instruction and will see what happens. If I don't see a difference I will then check to see if I am plugged up.

jeff216410 wrote:Is the Low Limit really 140? Also check the third parameter in the boiler aquistat which is the delta temperature. It can be 10-25F if I remember. If it is 10, then the boiler will not crank up the fire until 140-10=130 which by that point you are already going to fall below the 120F output. Try raising your Low Limit to 160 and check the next parameter in the display which is the delta; and set it to 10. This way 160-10=150 at which your boiler will be firing up and you will have some margin to allow the boiler to ramp up heat before getting down to the 130 range. I run LL170, HL 190 Delta 10. This allows me to fill a bathtub for the little ones because the boiler temp starts north of 170 and gives a lot of hot water in a short time but it pulls the boiler down to 120F. I've run 180F LL with a reduced fire in summer to have enough heat stored in the boiler for a sudden high demand, while not having a full coal bed so it does not hit the dump zone.