New boiler - leave Low Limit off?


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Old 01-13-14, 06:06 PM
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New boiler - leave Low Limit off?

Just installed a new Dunkirk DMX-170 Gas boiler over the weekend. I have a separate gas hot water heater.

The unit came with the Low Limit (water temp) set to OFF but installer originally set high to 190 and low to 150. Unit was kicking on way too often without call from the thermostat. I reset the Low Limit to 130 and it kicks on less frequently but still comes on without call from thermostat.

I have read other threads and saw one that says it can't be set too low or it will cause problems. The default was OFF and I've read elsewhere it can be off.

Looking for recommendations for all settings as it also has Economy setting in addition to High and Low.

Thanks! Ken
 
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Old 01-13-14, 06:21 PM
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Dunkirk DMX-170 Gas boiler
No mention of that model on their website... check the dataplate on the boiler to see if that's the right model name.

installer originally set high to 190 and low to 150.
"Bozo's Plumbing and Heating" , right?

You don't need it. Turn it OFF.

Looking for recommendations for all settings
What's the make/model of the aquastat control? Sounds like you have a "HydroStat" model... which one?

I believe you may have a DXL boiler?

If so, you have the HydroStat control.

Set the 'economy' setting to the number of zones that you have.
 
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Old 01-13-14, 06:29 PM
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By the way... a little late to tell you this... but:

That boiler is probably at LEAST TWICE as many BTUH as you need.

Unless you live in a 6500 square foot McMansion.
 
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Old 01-13-14, 08:05 PM
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Thanks, NJ. I live in an old house with multiple additions that comes to about 3,000 sq. ft. with a total of 12 cast iron radiators and 2 baseboard radiators. It's all on 1 zone. I replaced an old 150 BTU oil furnace.

It is a DXL -170 with the Hydrostatic. I now have the Low Limit off, High Limit at 180 and Economy on 1

Thanks again!
 
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Old 01-13-14, 08:26 PM
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about 3,000 sq. ft
Which would come in at about a heat loss absolute worst case of maybe 100K

And the replacement is even bigger yet than the old boiler...............

Nothing to do about it at this point I guess.

You'll still save a bundle switching to gas from oil so all is not lost.
 
 

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