Reducing Boiler Cycle Frequency

Reply

  #1  
Old 01-04-15, 07:19 PM
Member
Thread Starter
Join Date: Dec 2014
Posts: 9
Upvotes: 0
Received 0 Votes on 0 Posts
Reducing Boiler Cycle Frequency

I have a basic 5ish year old New Yorker natural gas boiler with a Honeywell FocusPRO 6000 thermostat. I'm in Minnesota but the weather has been fairly mild and my thermostat was cycling on every 5 minutes or so. Now that we're finally getting some steady well-below-freezing temps, it still seems to be cycling quite quickly. I'd like to change this so it kicks on every 30 minutes or so, even if it means the temp in my house fluctuates a degree or three. I've gone through the thermostat manual and ensured that all the settings appear correct, so perhaps I'm asking more than my current system can handle. Would I be wise to replace the thermostat? It seems like it might pay for itself in the long run on efficiency and prolonging the life of the boiler.

Here's the install manual for my current thermostat.
https://customer.honeywell.com/resou...69-2738EFS.pdf

Aquastat is a L 4080 B 1436. Some Googling suggests to that the range is 140-240.

My house is about 1300 square feet and the boiler apparently has an output of 45000 BTU. I figure that I have decent though not great insulation and windows. From what I can tell the boiler is more or less properly sized for my house, though I'm just trusting a few calculators that are out there on that.

Is there any other info I can provide? Does this even make sense? Essentially, my understanding is that the less frequent a boiler cycles the more efficient it will be and the greater longevity it will have. I'm striving for that goal even if it means sacrificing temperature consistency a bit. Thanks in advance.
 
Sponsored Links
  #2  
Old 01-04-15, 07:29 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 17,780
Received 7 Votes on 6 Posts
Make and model of boiler will help..

Also for reference tell us the psi and temp reading off boiler gauge.

Please also tell us what type of heat emitters you have in the home... cast iron? copper finned? etc...

Pic of the boilers piping and boiler itself would be great...

And last how is your hot water heated?

The T stat may not be the issue..
 
  #3  
Old 01-04-15, 07:39 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
Is the thermostat located on an interior wall?

Is the thermostat located away from the direct effect of a nearby heat emitter (baseboard/radiator)?

Where the thermostat wire exits the wall, is the hole around the wire sealed? Or is it possible that a cool draft is coming out the hole and causing the thermostat to short cycle?

To what do you have "FUNCTION 5" set to?

What temperature setting do you have the L4080 at?
 
  #4  
Old 01-04-15, 07:49 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
my thermostat was cycling on every 5 minutes or so
You're sure that the thermostat is what's cycling, right?

You observe it on the display?
 
  #5  
Old 01-05-15, 06:44 AM
Member
Thread Starter
Join Date: Dec 2014
Posts: 9
Upvotes: 0
Received 0 Votes on 0 Posts
It's a New Yorker CG30CNC-TE2. I've got the pressure at about 12-15 (cold-hot). I've got seven cast iron radiators that I'd call medium (on average) in size. Hot water is heated via its own power.

The thermostat is located on an interior wall in a hallway, though it's only ~10 feet from the (small-ish) bathroom radiator. Hole behind the wall is small, though I can shoot some expanding foam into hole for the thermostat wire in the basement if you think that might help. There's certainly no reason truly cold air should be rushing in and out of that hole. Function 5 is set to 5: gas or oil furnace.

I'll try to get more detailed info this evening, including looking at the aquastat and paying closer attention to the display of the thermostat when this cycling takes place. I believe the thermostat is involved, as I hear the click that it makes when this occurs.
 
  #6  
Old 01-05-15, 06:52 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
There's certainly no reason truly cold air should be rushing in and out of that hole.
No... one would think not, but it can effect thermostat operation, even if it's only a few degrees cooler than the room.

I hear the click that it makes when this occurs.
Is the thermostat new? I wonder if it could simply be defective?
 
  #7  
Old 01-05-15, 07:00 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
Function 5 is set to 5: gas or oil furnace
This is the 'cycles per hour' setting.

As experiment, try reducing that number and note the results.
 
  #8  
Old 01-05-15, 07:12 AM
Member
Thread Starter
Join Date: Dec 2014
Posts: 9
Upvotes: 0
Received 0 Votes on 0 Posts
The thermostat is new. It was installed by a contractor when I had a high velocity AC unit installed. I'll try sealing up the wall and playing with that cycles per hour setting to see if I can get more favorable behavior. I'll also see what I can find with the aquastat regarding settings and the real temp range that the boiler is showing as it cycles.
 
  #9  
Old 01-05-15, 07:09 PM
Member
Thread Starter
Join Date: Dec 2014
Posts: 9
Upvotes: 0
Received 0 Votes on 0 Posts
I verified that when the system shuts off it's the thermostat that initiates the change ("Heat On" disappears on screen). The aquastat appears to be showing ~155 degrees, but the gauge on the boiler appears to top off at roughly 130 degrees and 14psi.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: