Problem with Burnham Revolution Gas Fired Low pressure Boiler system Model RV4NSL-L2

lleddirs

I Own a Burnham Low Pressure Gas Fired Boiler and Indirect Water Sorage Tank High Efficiency System. The Model is Burnham Revolution Model RV4NSL-L2... It started locking out going into some kind of low flame mode where it wouldn't heat the water to the proper Temp in turn to heat the Water storage tank to the required temp. Here is what i wrote to another site...:



<span style="color:#000000">Hello.I seem to be having a problem with our boiler system that heats our indirecthot water storage tank. Boiler seems to be working fine at times & fires upokay, however occasionally it will do something strange and we have no hotwater... it seems to stop heating the water that flows in the boiler andthrough the storage tank to heat the stored hot water that is actually used inthe home. It will work okay again if we reset it by shutting it down andrestarting, but then something will trigger it to stop heating again but yet itruns on like a low flame or something and doesn't heat the water to thetemperature needed to heat the stored water in the tank. It’s driving uscrazy... Had a plumber look at once and he said there was air in the line (didn’tsay which line) and he released air and reset boiler and he said "that wasthe problem"... but now 7 months later it’s doing it again... Seems toalways stop working/heating the water after running the cold for a long periodof time which is strange in itself, for example… like after watering the gardenand grass for 20 minutes. Does anyone seem to know what this problem could be?After quite a bit of thought, I have determined that maybe it is sensing someproblem in the system and puts it into a low running mode of some sort... orpossibly it is not going into sleep mode properly after heating the water. I’vewatched it run normally and typically, I've noticed it fires up, heats the waterto the set temp, once it has circulated through the storage tank and heated thatwater to its desired temp, it goes into a sleep mode where it almost looks likeit’s off... and then when it senses the change in temp in the storage tank -or-someone uses a significant amount of the hot water, it fires up again to repeatthe process. The only difference when we lose hot water and it locks out insome way I guess you would say, is that it will fire up and run but the flameis a lot lower than normal heating times and I'm guessing that due to that, itwill only heat the water as high as it possibly can with that lower flame andthen continues to run like that until reset. And it will never go into sleepmode at that point because it hasn't sensed that the stored water is at its desiredtemperature yet, so it just runs and runs and runs on that low flame and nevershuts off... Not only do we lose our hot water, but I would assume we're wastinggas also because the stupid thing never shuts down for its typical break hereand there. Does anyone know what could be causing this and what can be done tofix it...? My brothers an electrician and installs and wires these things all thetime and he has tried to figure out the problem also and he can't seem to findwhat’s wrong. I'm wondering if it is just a confusion issue in the boiler becauseof it maybe sensing another external issue that we’re not seeing... or maybethere is an actual problem with the boiler itself, like maybe there’s amalfunctioning switch, board, or part of the flame is just not lightingcorrectly and it's only half lit strangely enough; or something beyond normalthinking. These are crazy guesses of course through imagining what could be theproblem. I honestly have no freaking clue here.... HELP ME PLEASE!!!</span>



Read more: <a href="http://www.doityourself.com/forum/boilers-home-heating-steam-hot-water-systems/473588-burnham-high-eff-gas-fired-boiler-system-locking-out-please-help.html#ixzz1yjuseBJd">http://www.doityourself.com/forum/boilers-home-heating-steam-hot-water-systems/473588-burnham-high-eff-gas-fired-boiler-system-locking-out-please-help.html#ixzz1yjuseBJd</a>

Tim McElwain

Just so we get the correct

information up front does this boiler have an Honeywell L8148E relay?



Does it have a Honeywell SmartValve system?



I recommend getting someone who is familiar with the Burnham Revolution to service it. I will contact someone locally at Burnham to see if they can get you someone.



In the meantime the electrician you have working on it you say is familiar with these units. If so did he check the VS3000 Water Temperature Sensor. This works off a thermistor and needs a resistance versus temperature check to make sure it is working. Did he take a differential pressure across the pressure switch? For the RV4 it should be .88" W.C. (water column) measured with a digital manometer.



Is this unit on Natural Gas or LP? Did anyone check the inlet and outlet gas pressure at the gas valve?



What is your location in the country?

Tim McElwain

Here is what the local Burnham rep says to look for:

While some of the things he addresses such as running the cold water for long periods of time have nothing to do with the boiler, other things do. I would focus on the two known issues that a Revolution boiler can encounter.

 

The boiler has a primary-secondary variable speed injection bypass system built into the boiler. It utilizes a variable speed injection control (VS3000) built for us by Tekmar to control the speed of a Taco 007 circulator on the return port of the boiler. The system flow comes through the bypass and back out to the system and the internal pump pulls some or all of the return water down through boiler and back into the bypass. A sensor on the supply outlet port of the boiler senses the temperature of the supply water to the bypass and either speeds up or slows down the internal pump. The transition temperature of the pump rpm is approximately 165-170°F. When the supply outlet temp falls below that it slows the flow down to pick up more temperature and when above it speeds it up to send it to the system supply. Two things can affect how this functions....one is the condition of that circulator and the other is the high limit setting of the boiler aquastat. The boiler uses an L8148E control with a high limit stop set for 210°F and a fixed 30°F differential. If someone saw this set for 210°F and turned it down to 180°F thinking it was too hot, it will totally affect the operation of the injection system and pump. If the boiler is functioning properly, as the internal temperature transitions through 170°F and eventually shuts the burner off at 210°F, then the internal pump will run at 100% and inject the boiler temperature to the system. Once the boiler cools down 30°F it will refire at approximately 180°F and the 100% output of the boiler pump will still be near 100%. If someone turned the limit stop down to 180°F then when the burner shuts off at 180°F it will have to cool back down to approximately 150°F before it turns back on again. This will bring the boiler temperature well below the pump speed transition point and the injection control will slow the pump down to as low as 13% normal speed to allow the boiler temperature to catch back up again. In other words as soon as the boiler temperature transitions the pump back to full speed it gets slowed back down again. As these pumps enter a slower speed they don't effectively cool themselves due to the slower speed and they can overheat internally. Keep operating this way for long periods of time in slow speed and eventually magnetite can build up in the internal cavities of the pump restricting their overall performance. The boilers are intended to have the limit stop set at 210°F to keep the pump at or near full speed once the limit has been reached. Turn the limit down and the pump will virtually always slow down and possibly overheat.

 

The second issue we have encountered involves the L8148E high limit. This control has a molex plug on the board to plug a vent damper into. Since this boiler is induced draft it does not use this feature and we configured it with a jumper plug. Early on Honeywell was wiring the wire on the pumper plug from the middle connector (6-pins) on one side to the corner connector on the opposite side to send the current through a resistor to simulate the resistance load of a vent damper. Early on some of the resistors (on circuit board of control) were burning out prohibiting the boiler to fire. We began requesting they rewire the jumper plugs to jump the power direct to B1 on the control by configuring from the center of one side to the center of the other or Pins 2 and 5 of the plug. This worked but approximately 5 years into the life of the L8148E we began to have other problems. Apparently what was happening is that the six pins for the damper plug were breaking away from the solder connections on the circuit board with temperature rises. When the boiler is shut down for a few minutes the circuit cools again and the connection is made again. Honeywell didn't know this was an issue because the warranty of the control was well beyond the one year period. We began sending some 5 to 8 year old controls back to them for testing and they found the soldering flaw. They supposedly have corrected it on new production replacement controls but time will tell. There is a temporary field fix which involves bypassing the vent damper plug circuit from B to B1 by installing a jumper from B1 to the B terminal on the high limit block. This is not the "politically correct" method of fixing it but it works when in a bind.

 

As you can see, neither of these issues is really a fault of the boiler itself or of Burnham but are caused by external circumstances. I would have them focus on these two issues first and then investigate other possibilities.

  

Tim McElwain

Something else to check

Also have them check to see if the sensor is still clamped to the supply outlet pipe between the flange and boiler. Earlier models used a plastic hinge clamp. Newer models have a tapping and well for the sensor adjacent to the supply outlet.

Tim McElwain

I guess I went to a lot

of trouble for nothing as the poster has not answered. I am actually getting a little tired of this happening maybe we should start charging for our services here.

shukmeister

Not a waste of your time.

Although the original poster did not reply to this thread, I found it extremely helpful and I really appreciate your time, knowledge, and advice.

We have a 2800sq. ft. rancher home with a revolution RV4PSL-L2 mfg. in 4/2001. We have hydronic floor heat with 5 zones, and a 6th zone for our DHW.

Anyhow, we have been having very similar problems with our boiler. We live in a very rural part of eastern Washington State, and getting quality local HVAC pros is a challenge. It costs enormous amounts to get guys out of Spokane, and even then it seems like a roll of the dice that you will find someone that won't scratch their heads at the problems we've been having. But they are still quick to charge $93 an hour to be confused.

For instance, the last pro we had from Spokane turned our boiler down to 180 to save us on fuel. However, the 80 gallon DHW tank is set at 130. The DHW keeps calling and calling, and the boiler runs and runs. The hot water only lasts about 45 minutes and then it takes several hours to recover. It has always been this way since we purchased the home in 2010.

2 weeks ago, the pressure relief valve began leaking. It turns out it had an iron sludge built up around the seat and so the seal failed. We shut the boiler down and closed the supply and demand water valves. The temp / pressure guage was frozen at 220 degrees - another victim of hard water I'm sure. (yes - we have a new water-right softener system.) 

We had the local guy come out for the easy fix, and when he fired the boiler up it came up to temp and the new pressure relief kept popping off. He did not have a replacement temp / pressure gauge so we had no way of knowing what the actual boiler temp was. So - we shut it down again. He thinks we need a new aquastat. He seems to think the hi-limit is bad in the aquastat. I have the older style Honeywell L8148E.

Anyhow, I am going to have these items replaced, but I also want to completely flush out my system to get rid of the mineral build-up. I am also considering buying a taco PC702. Any other words of wisdom you might have would be greatly appreciated.  

Zman

T&P valve

Did the guy who replaced your T&P (temperature and pressure) check your expansion tank? It seems far more likely that you have a waterlogged expansion tank rather than a failure of multiple controls. If the tank is waterlogged, the pressure in the system will build as the boiler heats up eventually discharging water through the t&p. You should be able to tap on the tank to get a general idea of it's condition. If it sounds like it is full of water,it is the likely culprit.

Carl



The OP also has some interesting info. Burnham certainly designed themselves into a corner on that one. Thank you TIM for your sometime thankless efforts.

shukmeister

What a mess

Zman - thanks for the response. When I get home tonight I will check into that.

From the homework I have done on this system, this set-up is a real mess. The zone valves are set up on the return side of the boiler, meaning the water flows through the zone first, then backwards through the zone valve, and back into the return side of the boiler. The DHW flows backwards too - in from the outlet, then out through the inlet and back to the return side of the boiler. I have been told that this is not really a big deal, but I have a hang up about things running the way they were originally designed to run.

In the original installation of the vent pipe, they used single wall galvanized venting with sheet metal screws at each joint. Of course this venting system was completely rusted out from acidic condensation, so we had to install the correct stainless steel double wall vent pipe with high-temp silicone at each joint.

Don't even get me started about how the floor heat and insulation are installed under the house. It will need to be completely re-done.

I am considering gutting out the entire installation and going with a geo-thermal unit. We have 2 water wells and I could use the well that is dedicated to irrigation for the geo-thermal unit. It may be time to cut my losses with this burnham system and start over. No offense to burnham - they make a great product when it is installed correctly.

  

shukmeister

expansion tank.

Zman - you are correct in your diagnosis. The boiler has been off for a couple weeks now, and so when I got home from work I promptly thumped on it and gently shook it. The water sloshed around inside, and it seems it is about half full of cold water. From what I understand about an expansion tank is that the only time it should have any water in it is when there is hot water expanding into it. With the system shut down and completely cold, the diaphragm should be pushing all of the water out of the tank as it waits for it to heat and expand against it. To double check, I tried the air valve stem. Instead of air, water came out. Definitely bad.



Good call! I will add this to the punch list of replacement parts. Thanks for the help!

shukmeister

more problems!

I know - I am probably getting annoying. Sorry about that.



Anyhow, I just keep finding more and more issues wrong with this system, and we have lived here for 2 and a half years!

I drained my boiler so I could take out the temp / pressure gauge and change it myself. The "water" that came out looked like chocolate milk! Is that normal?

Also - the circulation pump is mounted on the return side of the boiler. The install manual explicitely shows in the piping notes on pg. 44 the circulators must be attached to the supply side. I have read in another thread that "As viewed from the front of the boiler, the left front pipe is the return and the left rear pipe is the supply. Putting the pumps on the return will end up with them prohibiting the internal circulator to do its job of variable speed blending. They need to be on the supply where their discharge head will be reduced through the system piping by the time the flow reaches the return and internal bypass."

I am getting in over my head - but the REAL problem is we have had several "technicians" look at this system and none of them noticed these things. Why can't I find someone that REALLY knows these systems and can fix it RIGHT?



HEEEEELLLLLLPPP!!!!!!!