Boiler leaking

Sean246

I have a Burnham alpine boiler and Buderus st-150 indirect water heater.

Four days ago, I noticed the boiler was dripping water and had a technician look at it. The technician said the pressure was over 30, and the fault could be the expansion tank, the air vent, or a hole in the coils in the indirect water heater. Last night the leaking became a continuous stream of hot water, and the pressure was well over 30. I turned off the boiler and shut off the water of the whole house. After some time, the pressure went down to around 20 or less, but there has been a slow dripping after that.

Twenty days ago I had someone come to fix rusty hot water. He opened the plastic lid of the water heater/tank, removed the insulation, and then unscrewed all six screws without turning off the power or water. Then he asked his supervisor if the tank had pressure and realized that he should not open it. So he turned the water to the tank off and tightened all the screws and put the insulation and cover back. He turned on the water to the tank and boiler. As I remember, he drained a small amount of water from the boiler or the tank before or right after turning on the boiler. Things seemed to be fine right after that.

My questions:

What can be the causes of the continuous stream of hot water leaking? Does that indicate damages other than the expansion tank and air vent?

Is it possible that the unscrewing and screwing back of the water heater tank with water pressure and power caused this in somehow?

Thanks!

Mad Dog_2

Hmmm weird. Can you post some pictures of both units and Piping?  😊   I'm not sure what he was trying to do w the Buderus tank?  The excessive water pressure is from a bad expansion tank and/or Boiler feed valve.  The coil or HX could have a leak.  Is the water coming out of the relief valve? Or somewhere else?  Definitely need pictures. Thanks. Mad dog

Sean246

Thanks, Mad Dog! The water comes from the pipe that drips water occasionally under normal conditions. I turned off the boiler and the main water more than six hours ago and the pressure shown on the gauge is around 10. But it is still dripping a small drop of water about every second.

When the person came to look at the rusty water, he first said my water heater needed to be replaced. I said that the manual says it could be fixed by replacing a rod. He then returned to his car and came back and said he checked the manual and I was right on that. He then opened the plastic lid and removed the screws under the insulation without turning off something. From what I overheard, he was asked to check whether the screws were rusted but he removed them. He drained a small amount of water, probably from the boiler, not the tank. I only remember that I put a container under the pipe to catch the water when he did that.

clammy

Get rid of your service company they sound like idiots . Your buderus tank is by far the easiest tank to clean . Being the service tech did not first shut off the water only goes to prove he has zero experience , at one point these where the best most serviceable tanks around weak link was usually no one ever did the suggested annual anode inspection and replacement unfortunately. One would shut the main water off drain some water off the tank to relieve the pressure ,undo the bolts off the top of the tank ,inspect and replace anode rod . Drain rest of the tank using a brush clean the tank and the heating coil , flush all the debrie out of the tank . Re install new anode and put cap back on end of story . Personally I would pressurize the boiler to 20 psi ,close the boilers water feed and chk in 24 hours . The expansion tank , pressure reducing valve is easy enough to check . I think I would also check the boilers and the indirects safety valves inlet side to ensure that there is no crap blocking it from functioning properly . Also testing and checking safety valves functioning especially on hot water heaters and indirects is some thing that should be taken serious and checked yearly especially w hard water and a safety drip the valve can over a short period become partially blocked . Not all that familiar w burmhams alpine but all mod con require maintenance ,combustion testing to be performed at a mim yearly if not just flying blind until it hits a wall ,then just replace . To sum it up I have a buderus st150 I service it s over 30 years old it had close to 2 5 gallon buckets of calcium in it still worked some what . After cleaning the interior it was like brand new .
I think you need a real 1 st line service tech w hydronic experience not the bag carrier . Peace and good luck clammy

Sean246

Thanks, Clammy!

Here is my update:

Another service engineer replaced the expansion tank and the valve connecting directly to the pipe that drips water down. As soon as he turned on the water heater, water went out from the pipe as a small continuous stream. So he shut off and disconnected the water heater and no water leaks. So now I have heating but no hot water. He agreed that the problem with the heater is not a small hole in the coil.

I think the service guy who came 20 days ago somehow damaged the water heater. As mentioned, he didn't shut down or disconnect anything before removing the screws under the insulation. Replacing it is very expensive.

Sean246

What is my best option? I am thinking about getting the service company to give me a discount for replacing it as the guy who came 20 days ago did not follow the manufacturer's instructions. What causes this kind of failure on Buderurs st 150? Can the heater be repaired? Suggestions are appreciated.

Additional info: both the boiler and the water heater tank were installed less than 12 years ago.

Sean246

I live in MA. Installation Service providers are welcome to contact me.

clammy

So he replaced the boiler expansion tank and the boilers safety valve . The drip your getting is from the boilers safety valve ? Did the service guy check the boilers pressure and ensure that the pressure reducing valve is set and working correctly , possibly connecting another pressure gauge to a boiler drain to confirm ,if so have they at least isolated the indirect water heater from the boiler by shutting off both portable inlet and outlet to the tank and also lowering or temporarily disabling the aquastat on the indirect so it will not call . If the boiler safety does not pop then the indirect is indeed leaking and needs to be replaced sadly . At 12 years old and no maintenance or anode replacement that’s quite a good life span all things considered not all tanks would fair as well depending on the water quality and usage . Peace and good luck clammy

Sean246

Thanks a lot, Clammy!

Yes, the small water stream was from the safety valve (the open pipe with the tray under it in the picture). The service guy did not use a separate gauge. At that time, I only knew there is an inlet valve to the tank and was unaware of the return valve so I am not sure if he shut off both. I would guess he did. I don't remember seeing him lowering the temperature on the aquastat. But once he connected the tank to the boiler, water came out from the safety valve pipe immediately, and the water was cold (I shut off the system 8 hours before he came). He did not check the pressure reducing valve.

You bring up a very good point about the pressure-reducing valve. I did not know it could get the tank pressure into the boiler. How can I test it?

Another thing to note is that water dripped slowly a week ago and then it became continuous steam Sunday night. If it is a hole in the coil, the hole became much larger in a few days.

Sean246

I was thinking about opening the tank and visually checking the inside for holes. With both the tank return and cold water inlet shut off and the aquastat disconnected, I tried to drain water from the tank. With water being drained from the tank, I felt the hot water slowly moving from the boiler side to the tank along the tank supply pipe, which I assume connects to the coil. Does this indicate there is indeed a hole in the coil? I guess I will need to check how fast heat will move along the pipe when I don't drain water.




The service guy who came yesterday seems to be a good engineer and did things neatly and professionally, the opposite of the guy who came 20 days ago and knows nothing and is extremely unprofessional.