Above is a photo of the A Fulton boiler system. The components from left to right are as follows: feed water tank with the pump mounted on the bottom of it, boiler, and blow down tank. There is a water softener that is not show in the photo to the left and forward of the feed water tank. It is not shown because it had nothing to do with the fault at first glances revealed. This fact will be explained latter.
The task at hand is to find out why the boiler is not filling with water so that it can generate steam. First a basic overview of what the system is meant to do. City water is fed into the water softener. From the softener the water is delivered to the feed water tank. The pump under the feed water tank is tuned on when the boiler’s control system is near a low water state (Low water state will shut down the boiler for safety reasons). Therefore, overcoming the pressure of the boiler and filling it with water. Lastly the blow down tank is used to cool down the water and steam in the case of draining the boiler or blowing down the water callem.
The history of this system is that RF Macdonald Co has had many call backs of this fault. Technicians in the past few mounts have gone out to the sight turned a valve or pushed a rest button and been on there way to the next job or home. I was encouraged to do the same after talking to the last technician to fix the problem. The truth is that this boiler is still under warranty, and RF MacDonald is not making any money off services work. More importantly the owner of the tofu restaurant needs this boiler to operate because he can not make tofu without steam. Steam can not be made without water in the boiler.
The boiler will be filled with the proper amount of water when the control system should call for water, if:
It is a good unit.
There is a complete and proper path for the water to flow.
The boiler is calling for water.
There is proper voltage to the system.
All control setting are set correctly.
Feed water tank has water
More then likely everything is good to the feed water tank.
Pump is not on
It would appear that the boiler is not calling for water.
Boiler will call for water if
The controls are set properly.
The proper voltages are applied to the circuit.
The control panel is a good unit.
There is a complete path from the control to the pump.
Trouble shooting reveled that the relay that energized the pump contactor were not making a complete path.
I rest the relay, the pump turned on, the boiler filled with water, and began to make start the process to make steam.
Why when I rest the relay did the pump turn on? Did it shake loose? Is there a loose wire? Or is it something else? The only way to know was to watch the system run.
The boiler ran well used up enough steam for the control system to turn the pump on to put more water into the boiler. The pump did turn on, but looking at the sight glass I could not see that the water was going into the boiler. I lessoned to the pump and it sounded like the water in it was boiling. While lessoning to it I placed my hand on the feed water pipe to feel for flow. All I felt was a lot of heat. There should be no heat on that line because the feed water is cold and there is a check valve between the pump and the boiler. Yes the only way that can happen is if the check valve is a bad unit and the reason resting the relay worked is because it reset an overload circuit in the relay.
The shiny part of the brass in the photo to the left is were it buy-passed.
In conclusion with my new techniques in troubleshooting and a basic knowledge of how boiler feed water system work I believe that I have solved this problem for good. Before taking this class feed water problem were some of the hardest thing for me to troubleshoot. In fact when I got told to go to this job I was not sure I would be able to help because I do not no much about pumps and there was no documentation on sight.
There was one more major problem I found in the system when I blow down the boiler. It blew hot steam right into the kitchen under the cook feet. It had nothing to do with the problem, but it is a safety concern and kind of interesting to summarize in my conclusion. I could not believe any one would pipe hot steam into a place were people could get burned. The problem was not were it was pipe, but that it was still hot. I called my boss and he expanded that a blow down take mixes the hot water and the steam with cold water to cool it off . When I Looked at the blow down take there should have been a thermostat and cold water piped in, but there was not.
This job thought me a lot. Of cores I learned more about the way things work, but it showed me to look at the whole picture, and that I can do a lot more then I think I can if I take the time to put it into a logical order.