Radiant Heat Leaking after Installing brand new boiler

olsondi

Hi there,

I have a concrete slab with radiant heat ( house built late 1970s). We recently replaced the boiler with a brand new one at great expense (9K), and in the last month we have had one huge leak that required 2K in repairs to jack hammer the concrete, repairs to the pipes, and then reconcrete. Then in the last few days we've started hearing a hissing sound and noticing a darkening of the concrete in an entirely different area. We suspect that we have an air leak in this spot. The contractor who installed the new boiler swears the leaks/problems have nothing to do with the new boiler, but I cannot believe that after 40 + years, these leaks are just a coincidence. Can anyone confirm whether the presence of a new boiler can change the pressurization enough to cause leaks where there were none or is this just a complete coincidence? Also, is there any other way to detect this air leak without breaking into the concrete? We have finished polished concrete on the floors and liked the rough/loft look, but it is starting to look ridiculous. Any input would be welcome.

Zman

What pressure is the new boiler running?
What type of tubing?
IR Cameras are good tools for finding leaks.
Carl

Gordy

When the installer did the new boiler did he pressure test the loops in the concrete?

No the new boiler would not cause the leaks.

It's quite possible the system was purged with city pressure, which may have been enough to take an already failing piping system, and pushed it over the edge. Not wrong in purging that way it's how it's done.

I assume copper in concrete? If so the results of longevity can be all over the graph it depends on how much flyash was in the concrete mix. Flyash is very corrosive to copper. Another variable is soil conditions if the copper was possibly not fully encapsulated in the concrete, and laying on a corrosive soil make up that can do it.

Me I have had good luck 63 years no leaks

Edit: is your make up water valve on, or off?
What psi is the boiler set at, 12-15psi?

Snowmelt

That's jus to the way it is.

olsondi

All good questions. I'll have to look into details tomorrow and post again. Thanks for trying to help me problem solve!

Snowmelt

One time I fixed a water heater and the shower diverter was clogged. I used viega so I don't solder I made a total of 4 presses with three fittings. Two femal - press and one ball valve. Water is very tricky.
-

tjorn

Did the contractor clean the system before putting the new boiler in? It is possible if he cleaned the system that he cleaned years of scale of a corroded system therefore finding a leak that was not leaking before? This wouldn't happen if it is pex but if it is metal piping entirely possible.

Ironman

It's not unusual to see metal piping in concrete leak after 40 years. And you're not leaking air, you're leaking water: a boiler circulates water.

There's nothing that I could think of that your installer could have done WRONG that would cause the leak, assuming boiler pressure is normal.

As pointed out already, street water pressure is used to purge the piping of air.

Tinman

Most of us, who have been doing this long enough, can relate to your contractor's situation...working on something, doing everything the right way, and an inevitable negative consequence occurs as a result.

RobG

Ironman said:

It's not unusual to see metal piping in concrete leak after 40 years. And you're not leaking air, you're leaking water: a boiler circulates water.

There's nothing that I could think of that your installer could have done WRONG that would cause the leak, assuming boiler pressure is normal.

As pointed out already, street water pressure is used to purge the piping of air.

Agreed, coincidences suck but they are just that, coincidences. You may want to consider alternative heating methods as the leaks will just keep popping up. The more make-up water that is going into your new boiler will kill it in short order. You could go with panel rads or ceiling/wall radiant or possibly an over pour. Any way you choose will be costly.

Paul Pollets

Levitt systems have a 50 year life expectancy. They will fail and its just a matter of when. We always pressure test the system before a boiler replacement, but exclude any warranty on the original system. We warn owners of these systems that they need to understand they have a life expectancy that will cause grief in the future. It softens the blow when the inevitable happens.

Bart Vaio

If the boiler is installed or setup improperly it can cause or exacerbate leaks. We have quite a few clients with slab Eichler homes from the late 50's to mid 60's in our area. Some steel pipe systems still around. The piping is fragile due to age so new boilers should be setup carefully, lowest allowable pressure, properly sized and pressurized expansion tank, treat the new water with Fernox, and most importantly if they replaced the main system pump it must not be oversized.

Gordy

Pretty hard to baby that. All your doing is prolonging the inevitable that is a question mark as to a period of time. I like Paul's approach a synopsis to the customer of what's down the road.

Ironman

Since the OP has not responded back, it makes me wonder if they were looking for answers or trying to find someone to agree with them that the installation of the new boiler was the cause of their problems.

It's quite evident to anyone who even casually scans through this site that the pros here are quick to point out anything that an installer does wrong; we're noted for that. In this case, I can't find anything that a boiler replacement would have caused, assuming the pressure is correct on the system and nothing caustic was introduced into it. Unless something else can be shown that is relevant, I can't see how the installer is at fault.

Gordy

Bart Vaio said:

If the boiler is installed or setup improperly it can cause or exacerbate leaks. We have quite a few clients with slab Eichler homes from the late 50's to mid 60's in our area. Some steel pipe systems still around. The piping is fragile due to age so new boilers should be setup carefully, lowest allowable pressure, properly sized and pressurized expansion tank, treat the new water with Fernox, and most importantly if they replaced the main system pump it must not be oversized.

How is this really being careful? The precautions you state are normal everyday procedures. System pressure has to be what it needs to be to allow flow to the high points in the system. Circulator sizing should always be only what is needed for required flow rates.

Gordy

Ironman said:

It's not unusual to see metal piping in concrete leak after 40 years. And you're not leaking air, you're leaking water: a boiler circulates water.

There's nothing that I could think of that your installer could have done WRONG that would cause the leak, assuming boiler pressure is normal.

As pointed out already, street water pressure is used to purge the piping of air.

I would have liked to have seen some pictures of the pipes repaired. Was the failure from the outside in, or inside out? In straight run or bend.

That could tell two different stories. Concrete, or soil aggressive to pipe. Agressive water, or over pumping.

Again neither could be attributed to installation of the new boiler.

j a_2

What type of boiler is it…Some, and Rinnai comes to mind require a higher static pressure to operate…But all that aside, there should be no blame on the contractor..He, worse than you, I am sure did not want a problem…He is a lic plumber/contractor I hope? If not, its not a good thing….For him or you...

j a_2

Time to call your ins. company…They will generally cover opening and closing but not the repair of the problem…Usually opening and closing is the worst of it, most definitly in your case…They all ask questions? And request paperwork...

hot_rod

Was there a discussion about installing a new boiler on a 44 year old radiant piping system, before you signed on?

j a_2

Question, why was the old boiler replaced ? Was your fill valve always left on, it may have been covering up a small leak under the floor….Did it and do you now have a low water cutoff sw. ? I just do not agree its the installers fault….Fill valves are made to fill the system, then shut them off…Let the system talk to you…don’t cover it up with a blanket….If your one to leave it open then at least put a water meter on it,and look at it every so often...