Spa Heater (Laars) Won't Stay On

All,
Thanks in advance for whatever help you can give.
Bottom line: My Laars EG-125 gas heater will ignite only briefly before shutting off. The heater light is on, it has a new pressure switch, new circuit board, new 2-speed pump, I have removed the filter and cleaned the jets.
The two ways I can get it to turn on are: 1. Flip it off and then back on 2. "Bump" the heater or heater pipes with my hand These two methods will make it fire for about 3-10 seconds before it turns back off.
What could it be? Where do I start?
Here's some additional background info if you are interested:
It is a 500 gal Catalina Boca Grande spa with a brand new Dura-glass 2-speed, 240 volt pump. I just replaced the orginal RC-4 circuit board with a BL-40 universal board. The pump starts and runs fine. The problem is the heater.
My heater is a Laars EG-125 with a recently replaced pressure switch. After the pressure switch was replaced the heater worked fine for a couple of hours. Now it will only work (and even then only briefly) if I hit it with my hand or flip the on/off switch.
Thinking that maybe there was not enough water pressure to make it fire, I removed the filter and removed all the jet nozzles to make sure they were not blocked. They were partially blocked with rust particles so I cleaned them out. I replaced the jet nozzles back in their places and fired up the spa. It then heated to 110 degrees with thermostat turned all the way up! I turned it off and then restarted it the next day. It now will only ignite if I turn the heater off and then back on or hit it with my hand. It only ignites for 2-5 seconds before shutting down again.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Additional info: when I turn the thermostat up or down, I hear the "click" of the relay opening and closing. Thermo would seem to be working...

with
After
I
if
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hi Brent, hope you are having a nice day
On 07-Dec-03 At About 06:04:07, Brent M. wrote to Brent M. Subject: Spa Heater (Laars) Won't Stay On
BM> All,
BM> Thanks in advance for whatever help you can give.
BM> Bottom line: My Laars EG-125 gas heater will ignite only briefly BM> before shutting off. The heater light is on, it has a new pressure BM> switch, new circuit board, new 2-speed pump, I have removed the BM> filter and cleaned the jets.
BM> The two ways I can get it to turn on are: 1. Flip it off and then BM> back on 2. "Bump" the heater or heater pipes with my hand These two BM> methods will make it fire for about 3-10 seconds before it turns BM> back off.
BM> What could it be? Where do I start?
BM> Here's some additional background info if you are interested:
BM> It is a 500 gal Catalina Boca Grande spa with a brand new Dura-glass BM> 2-speed, 240 volt pump. I just replaced the orginal RC-4 circuit BM> board with a BL-40 universal board. The pump starts and runs fine. BM> The problem is the heater.
BM> My heater is a Laars EG-125 with a recently replaced pressure switch. BM> After the pressure switch was replaced the heater worked fine for BM> a couple of hours. Now it will only work (and even then only BM> briefly) if I hit it with my hand or flip the on/off switch.
BM> Thinking that maybe there was not enough water pressure to make it BM> fire, I removed the filter and removed all the jet nozzles to make BM> sure they were not blocked. They were partially blocked with rust BM> particles so I cleaned them out. I replaced the jet nozzles back in BM> their places and fired up the spa. It then heated to 110 degrees BM> with thermostat turned all the way up! I turned it off and then BM> restarted it the next day. It now will only ignite if I turn the BM> heater off and then back on or hit it with my hand. It only ignites BM> for 2-5 seconds before shutting down again.
Don't you think you should call someone who knows what they are doing to look at it? you have practically rebuilt it and you still have the problem. you would have spent less money had you called a pro in the first place.
-=> HvacTech2 <=-
.. "After they make styrofoam, what do they ship it in?" - s.w.
___ TagDude 0.92+[DM] +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ spam protection measure, Please remove the 33 to send e-mail
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.