Aquastat Relay issue and question

Old 01-26-10, 08:53 AM
Thread Starter
Join Date: Jan 2010
Location: New Jersey, USA
Posts: 1
Upvotes: 0
Received 0 Upvotes on 0 Posts
Red face Aquastat Relay issue and question

I don't have a great understanding of how the electrics of my furnace works but i do have two zone heating, gas, base board hot water.
I started having an issue last week where the heating was not coming on when the timer requested it so i came home to a cold house. The two circulation pumps were running and the pilot light was one. So on investigating i took the cover off the Honeywell Aquastat Relay (Type L8148E), as soon as I touched it i heard a clicking at the bottom of the furnace right where the gas is fed in. I am guessing the relay tells the gas to turn on. Well it worked but only until the next day, same thing happened. So fiddling with the relay eventually gets the gas to flow.
I don't see any loose wires but basically now it keeps happening and pushing/pulling gently on the relay I will eventually get it working again.
Any idea what the issue might be? Is the relay gone bad, or is there a loose wire i can't see? I have already agreed to sell my house and i don't want to give it to the new owners in this condition.

Old 01-26-10, 08:45 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 12,674
Received 40 Upvotes on 38 Posts

I suspect there is a bad solder joint on the circuit board of the L8148E. This is not an uncommon problem. Some where on the case of the control (usually printed on the end) should be the L8148E followed by a four digit number. Here is a link to a place where you can by the control after checking for those last four digits.

Patriot Supply -

If neither of these matches yours, please post the complete model number (L8148E-xxxx) & I will try to cross reference it for you.
Old 01-22-13, 06:19 AM
Join Date: Jun 2009
Posts: 145
Received 0 Upvotes on 0 Posts
The Aquastat Relay Type L8148E - 1257 is what I see on the inside white tag. Also, is there any way that I can manually trip or turn this Relay on when the thermostats are calling for heat (temporarily) or there is nothing I can do short of replacing the unit. If I replace the unit does the boiler have to be drained? Could it also be the electronic ignition or a combination of? I will try to post pictures in a few minutes. Thanks!

Last edited by Catanzaro; 01-22-13 at 06:58 AM.
Old 01-23-13, 05:40 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 12,674
Received 40 Upvotes on 38 Posts
I believe the aquastat to be the source of the trouble & replacement is the only option. You do not have to drain the boiler to replace the aquastat, but you must turn off the power at the wall switch or breaker panel.

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