Ek system 2000 intermittent issues

j_hadden

I bought this house a few years ago with a system 2000 with classic manager (1997). One issue that has been recurring but intermittent is it going into hard lockout mode.  I suspected the primary controller and changed it out for a r7284u but the issue remains.  I now have a better idea of the fault though.   When thermastat calls for heat, it starts up fine, yellow led illuminated and primary has power and cycles fine.  Zone opens up fine however when call is satisfied the boiler continues to run. When the red led shuts off the  circulator led remains on, there is still a signal at the TT terminals. During this time the Boiler will fire for about a minute then flame out 3 times before going into lockout.  It doesn't happen every cycle but often enough to be annoying.  I suspect the dual limit aquastat to be faulty or possibly the manager. I have been searching for answers with no luck and local system 2000 guy says he found nothing  wrong.  Anything I'm missing?

EBEBRATT-Ed

I am not an EK expert but if the burner is going off on FF I think you have a burner issue

HVACNUT

Hard lockout on the burner? You need to press the reset on the primary?
The "flame out 3 times before going into lockout" seems like its going into recycle so likely a fuel delivery or combustion issue. Not really DIY. 
I don't think you need to be a "System 2000 guy" to figure this one out but using an EK dealer would be best. Maybe ask for a senior tech or the Service Manager to come out.
Let us know how you make out.

szwedj

Once a thermostat call is satisfied, and the thermostat input light on the left side goes out, the burner light will also go out (the burner should only run during a call for heat). The manager open and closes TT, so if the burner is still running after the burner light goes out, the most common cause is that TT is jumpered on the primary. If there is no external jumper on the primary at TT, then most likely TT is configured as "closed" in the controls setup and needs to be set to "open".

I should add, even with TT staying connected, that would not cause the burner to lock-out and that still needs to be addressed here.

I don't know how this system is vented, but sometimes on power vented systems that have the burner TT jumped, the inducer post purge can time out before the zone post purges resulting in the puff switch opening FF causing the burner to lock out.

j_hadden

Most times it runs perfectly fine and is not locking out due to flame out.  The problem occurs during shutdown and I believe it's only during specific circumstances. I am confident that there's nothing wrong with fuel system or burner but rather a wiring or configuration issue. 
TT is wired to B1B2 on manager and has 24v even  after  call light and burner light goes out, circulator lights stay on. If I understand it correctly, that once a call is satisfied then there should be no power to TT and burner light goes out.  Zone and circulator remain on for a bit before shutting off.
"I don't know how this system is vented, but sometimes on power vented systems that have the burner TT jumped, the inducer post purge can time out before the zone post purges resulting in the puff switch opening FF causing the burner to lock out." This may be what's happening.  I have a power vented system and when it acts up its always during this purge.  Seems to me that this unit is powering TT during this purge until it hits the the high limit, however the error occurs if the purge period ends before the high limit is reached. If this happens TT is still calling for heat but the puff switch is not allowing fire and prompting lockout therefore high limit is not reached.  This explains the intermittent pattern.

My question now is how to correct it.

szwedj

Any service tech can call the factory for tech support if they need some assistance with this. The best time to call is while they are there in front of it. Another option is to call customer service at 1-800-323-2066 and ask them for dealers that service your area.

Jamie Hall

"If I understand it correctly, that once a call is satisfied then there should be no power to TT :"

There is a misunderstanding here: T-T does not need a voltage on it or power to it. All it needs is a closed circuit. When the burner is called, there will be zero volts across T-T, although there may be -- depending on how things are wired -- 24 volts or so to ground from one T or the other when the call is finished.

Robert O'Brien

j_hadden said:

Most times it runs perfectly fine and is not locking out due to flame out.  The problem occurs during shutdown and I believe it's only during specific circumstances. I am confident that there's nothing wrong with fuel system or burner but rather a wiring or configuration issue. 
TT is wired to B1B2 on manager and has 24v even  after  call light and burner light goes out, circulator lights stay on. If I understand it correctly, that once a call is satisfied then there should be no power to TT and burner light goes out.  Zone and circulator remain on for a bit before shutting off.
"I don't know how this system is vented, but sometimes on power vented systems that have the burner TT jumped, the inducer post purge can time out before the zone post purges resulting in the puff switch opening FF causing the burner to lock out." This may be what's happening.  I have a power vented system and when it acts up its always during this purge.  Seems to me that this unit is powering TT during this purge until it hits the the high limit, however the error occurs if the purge period ends before the high limit is reached. If this happens TT is still calling for heat but the puff switch is not allowing fire and prompting lockout therefore high limit is not reached.  This explains the intermittent pattern.

My question now is how to correct it.

Replace primary with a Carlin 70200 and wire puff switch to blocked vent terminals, will also give you valve on delay assuming you have an oil valve

j_hadden

Ok bear with me as this is not close to my trade (biologist)  but I used to be a mechanic.  I am now aware that the B1B2 terminals are dry contacts and only open or close.  So far what I have found is a break in the B2 wire. Fixed that then configured the primary to open on TT. Its been running as it should for 24 hours now.  As far as I understand it, the fault occurred when the TT was closed, it continued  to operate the burner, but when the post purge cycle completed before the burner hit the high limit, the puff switch opened the the circuit, showing a flame failure and ultimately going into lockout. This explains the intermittency of the fault. Fingers crossed that it actually fixes it but I won't know unless it goes into lockout again.

"Replace primary with a Carlin 70200"
So I actually have one new in the box and had intended that to be a replacement but long story short, I ended up with the r7284u and using that now.

HVACNUT

Props to @szwedj for that one. 
I don't even know why it gives you the option. Is it that hard to put a jumper across TT if needed?

szwedj

@hvacnut we run into this from time to time. When TT is jumped/closed, on a chimney it typically overheats the zone or hot water, because the burner stays running during post purge. On power vented systems the inducer post purge is fixed at five minutes but a heating zone can purge up to 20 minutes which will cause the puff switch to open and lock out the burner.

It used to be that a jumper would be installed by mistake, now some of the controls with the programmable TT option come pre-programed with TT "closed"

A sure sign is when the burner running while the burner light is off.