DIYnot
Local | Network
   DIYnot > Forums
Local | Network
DIYnot Network Local DIYnot Network Local  
  Forum IndexForum Index     RulesRules    HelpHelp     Join FREERegister Free     About CookiesCookies     SearchSearch     LoginLogin 

HIGH LIMIT / LOW LIMIT / OVERHEAT STATS


 
Post new topic   Reply to topic    DIYnot.com Forum Index > Plumbing and Central Heating
Search this topic :: View previous topic :: View next topic  
Author Message
jackecole

from United Kingdom

Joined: 29 Oct 2008
Posts: 433
Location: London,
United Kingdom
Thanked: 16 times

PostPosted: Sat Oct 30, 2010 11:31 am Reply with quote

WHat's the difference between a high limit stat, a low lmit stat, overheat stat etc? I know some boilers use a combination of the above but what's the difference?
Back to top
 Alert Moderators

If you do not want to see this advert, click here to login or if you are new click here to join free.
kevplumb

from United States of America

Joined: 18 May 2004
Posts: 23673
Location: Georgia,
United States of America
Thanked: 918 times

PostPosted: Sat Oct 30, 2010 12:22 pm Reply with quote

all the same just trip/switch at different temps icon_razz.gif
Back to top
 Alert Moderators
jackecole

from United Kingdom

Joined: 29 Oct 2008
Posts: 433
Location: London,
United Kingdom
Thanked: 16 times

PostPosted: Sat Oct 30, 2010 12:25 pm Reply with quote

Thanks for the quick reply kev

I take it a low limit stat is just your normal user stat/thermistor then?

High limit being same as an overheat?
Back to top
 Alert Moderators
kevplumb

from United States of America

Joined: 18 May 2004
Posts: 23673
Location: Georgia,
United States of America
Thanked: 918 times

PostPosted: Sat Oct 30, 2010 12:32 pm Reply with quote

low limit stat is usually found on solid fuel
it stops the pump running till the boiler is warm enough to stop condensation forming

frost stat is sometimes called a loww limit stat as well

yeah high limit / overheat same animal icon_wink.gif
Back to top
The following user says thank you to kevplumb for this useful post:
jackecole (30 Oct 2010)
 Alert Moderators
spraggo

from United Kingdom

Joined: 06 Sep 2010
Posts: 910
Location: Avon,
United Kingdom
Thanked: 149 times

PostPosted: Sun Oct 31, 2010 10:42 am Reply with quote

jackecole wrote:
WHat's the difference between a high limit stat, a low lmit stat, overheat stat etc? I know some boilers use a combination of the above but what's the difference?


These high and low limit stats were used on the old Thorn Apollo etc. They were activated by a rocker switch on the control panel marked high and low. The purpose of these, where to enable the user to select low in the mild weather and high in the cold weather. These two button type stats were fitted to the flow inlet side of the primary heat exchanger and were marked with a coloured dot to indicate their temperature at which they opened, which ranged between 135F and 190F.

The overheat stat shuts the boilers down if the water temp goes to high if either of these two stats failed
Back to top
 Alert Moderators
namsag

from United Kingdom

Joined: 12 May 2004
Posts: 9909
Location: United Kingdom
Thanked: 321 times

PostPosted: Sun Oct 31, 2010 10:53 am Reply with quote

Wee bit mixed up there Spraggo a low limit stat is different from a lo stat that was on appollos.
In domestic situation a low limit stat is what you get on warm air units ,burner comes on and the unit has got to get to a certain temp before the fan kicks in so that its not blowing cold air to start with
Back to top
 Alert Moderators
spraggo

from United Kingdom

Joined: 06 Sep 2010
Posts: 910
Location: Avon,
United Kingdom
Thanked: 149 times

PostPosted: Sun Oct 31, 2010 11:22 am Reply with quote

namsag wrote:
Wee bit mixed up there Spraggo a low limit stat is different from a lo stat that was on appollos.
In domestic situation a low limit stat is what you get on warm air units ,burner comes on and the unit has got to get to a certain temp before the fan kicks in so that its not blowing cold air to start with


Thankyou for your correction namsag and I apologize, I was refering to high and low stats, not high and low limit stats.

spraggo
Back to top
 Alert Moderators
spraggo

from United Kingdom

Joined: 06 Sep 2010
Posts: 910
Location: Avon,
United Kingdom
Thanked: 149 times

PostPosted: Sun Oct 31, 2010 12:06 pm Reply with quote

spraggo wrote:
namsag wrote:
Wee bit mixed up there Spraggo a low limit stat is different from a lo stat that was on appollos.
In domestic situation a low limit stat is what you get on warm air units ,burner comes on and the unit has got to get to a certain temp before the fan kicks in so that its not blowing cold air to start with


Thankyou for your correction namsag and I apologize, I was referring to high and low stats, not high and low limit stats.

Please refer to the "similar topics" at the bottom of this page, where they are referred to as limit stats, whats the difference?.

spraggo
Back to top
 Alert Moderators
Search this topic :: View previous topic :: View next topic  
Post new topic   Reply to topic    DIYnot.com Forum Index > Plumbing and Central Heating All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
Similar Topics   Replies   Views   Posted 
Thorn Apollo high/low limit stats colour code 4 560 Fri Dec 21, 2007 8:28 pm
Honeywell Low & Hi limit pipe stats 19 3600 Mon May 16, 2011 10:20 am
Problem with limit thermostat or overheat cutoff thermostat? 2 80 Fri Jun 15, 2012 9:44 pm
Will changing high limit thermostat help 01 fault (vokera) 2 640 Wed Jan 20, 2010 10:58 am
Powermax 155 High Limit. 5 360 Fri Jul 23, 2010 7:36 am


 
DIYnot
Find an Expert | Find a Supplier | Search DIYnot.com
Network | Advertising | Newsletter
DIY | DIY How To | @home | DIY Wiki | DIY Forum
By using this site you agree to our Terms of Service / Disclaimer.
Please read our Privacy Policy. Copyright © 2000-2014 DIYnot Limited.