Radiant Hydronic baseboard sys keeps bursting. - seeking guidance

zarkbuilder

Hello Experts,
We're a bit frustrated as the radiant hydronic baseboard system has burst (freezing pipes) for the third winter in a row. interior house damage this time is significant (ugh). details below. Seeking guidance on several levels:

a) how to determine that a licensed plumber is knowledgeable in radiant?
(I will reach out to an advertiser who is more than an hour from my location, but incase I am too far.......)
b) what DIY items can I look at now to bandaid the situation?
c) what should I/plumber do next season to avoid bursting pipes?

background: Ohio Valley location. Solid brick two story house 90 years old. Exterior brick in excellent condition, plaster interior, no 'modern' insulation, windows are 20 y/o insulated type. After elder passed, house is lived in part-time. During Winter months, house can be empty for long periods.

System: Separate Radiant Hydronic baseboard systems were installed more than 15 years ago for each floor. Boilers are clean and look like they were installed yesterday. The open ceiling unfinished basement displays piping going everywhere. We labeled almost all the pipes/valves years ago to reduce confusion. When the systems work, whole house is very comfortable.

Symptoms: the Second floor has burst almost every the time, on the shady side of the house, the (absolute?) farthest point from the boiler source. The first burst, the plumber found a brick within the chimney had fallen into the exhaust(?)/flue of the boiler eventually shutting it down. Second burst, there was an unusual sudden significant drop in outside temp below 0F that lasted for many days. Plumbing Co. said they had hundreds of calls. OK, bad luck maybe.

Current Setup/problem: Third year in a row, burst occurs, but nothing appears unusual. We set both thermostats ('old' honeywell dials) to 70F while gone. In advance of a temp drop, we increased the thermostats to 80F. Outside low touched 10F for two nights, then low was in the 20Fs. Day time in the 30Fs. Never lower this winter. Neighbors say no power failure. We asked neighbors to lower thermostats back to 70F, massive second floor flooding discovered. #$%&. These low temps were not that cold. It is a HEATING system after all. .....And, I'm not in the Yukon. I insulated all the hot copper pipes in the basement ceiling upto the point they elbow upstairs. I find it curious that the bursts occur in the highest area in the house where heats rise, but contradicting this is the area is the furthest from the boiler.

Plumber: We have been using the same large plumbing company that has about 15 trucks and does primarily residential work in our and surrounding areas. Yes, they know radiant heat. or maybe they dont. the repair work is expensive, but some of the older guys know the older systems and know how to get the parts. They have repaired and checked the system numerous times in the past three years. One problem is they send different guys to our house. Sometimes for the same repair. Pro fixes a problem, but no knowledge acquired by them about my house and none shared with me. My faith in them is lost. I learned very recently that anti-freeze may be able to be added to a radiant system. They never told me that.

I am DIY capable. I have a Plumbers wrench, I have a pipe cutter, I do not want to weld (thats for the pros), I can test some electric circuits with a ohm meter, I've installed my own house toilets (after the original plumber did not level them correctly years earlier). So I can figure out stuff, but I do not pretend to be a Plumber.

In addition to my Questions a,b,c above, I have some other not-brilliant questions that I am hoping I can get some guidance on:
-If anti-freeze can be added, where? I do not see any obvious inlets.
-Can the whole system be drained? We have a drain for the cold running water in the house (sink, bath, etc.), but not any other pipes as far as I can tell. it is a maze.
-Water leak alert systems. more than 5 years ago, i looked into this, but they were considered very inaccurate (moisture conditions create false alarms). Some monitor water usage, others monitor for flooding. Any suggestions for stand alone flood alarm OR complete systems (that are part of a house security system)?
-below freezing temps are almost over. Placing an electric heater in the basement and turning both radiant systems off for a few months. Pros/Cons?
-I have a laser thermometer. What temp should it read on the hot pipe surfaces in different locations? Exiting boiler? 50 feet away in basement? first floor? second floor?
-What should the hot water RETURN pipe be before re-entering the boiler? I am sure distance is a factor.
-AFTER repairs (in the future) by a pro, how do I confirm there is no air in the system?
-Can setting the thermostat too HIGH, be a problem?
-What are the common reasons for radiant pipes bursting that you have seen?

I hope to locate a small plumbing outfit that knows radiant, will learn this old house, and teach us how to prevent future disasters.
Thank you for taking the time to read our issue. Your suggestions are appreciated.
Ark Building has begun.........

yellowdog

The first thing to do is to find the split pipe that caused all the flooding. Now look in that immediate area to see why that pipe burst in that specific location. Then fix the reason the pipe burst. It could be a pipe run too close to an outside wall. There could be a pipe that is no longer covered by insulation in the attic. Step one is to find the source of the water.

psb75

You need to thoroughly inspect the places where the plumbing froze and split--present AND past. Look for patterns of "why here--specifically?" Given your history and description of the building and how it is operated, glycol is highly recommended. Yes there are several places to fill the system. Yes you can drain any system. Glycol is expensive and is hard on system components. It is a necessary "band-aid." You should also have a way to carefully monitor the interior temperatures remotely in order to catch the problem EARLY. There are systems that send emails and phone calls to you and service people.

GGross

Pipes burst generally due to freezing. If your boiler locks out and can't heat the water, and you are not there for enough time that sections of the pipe freeze, they will burst. I recommend some glycol for anyone who is not going to be in the building for a length of time during winter. If your heating system pipes are bursting a wifi thermostat, or any way to monitor the house temperature remotely is an incredibly easy way to prevent this, once the temperature inside starts to drop you know the boiler isn't working and could call someone to repair it before a pipe bursts, glycol should still be used, but you likely don't need that heavy of a concentration . I am shocked that after 3 bursts not a single pro suggested either of these simple investments, I am even more surprised your insurance company hasn't required these things to be done to prevent future payouts. If you have pipes running near outside walls, providing better insulation on those walls will add to the time it will take for your system to freeze. It usually takes quite some time for bursting to occur if you were to have even a weak concentration of glycol.

Water leak systems are nice to put under fixtures etc. If your heating pipe bursts though it is almost certainly due to freezing, and once the leak detector goes off the damage is already done. I'm not saying you shouldn't install one, just don't let it be the only thing protecting you.

If your boiler has an automatic fill valve installed, you should really figure out if your system has leaks and really needs an autofill.. If its leaking its not a great one to leave without someone to look after it. When your pipe bursts, it may be frozen at first, but eventually that will melt and once it does the fill valve will continue adding water to the system that will just come out the burst location adding to damage

Jamie Hall

I'm quite sure there is a way -- though it may be a bit tricky -- to add glycol to your system. To figure out how, a few pictures in the vicinity of the boiler would help.

And yes, I know glycol is a nuisance. So, however, are frozen pipes...

Now the two suggestions above mine here are good, but there's more. A baseboard system should circulate at least once -- preferably twice -- every hour. How long it needs to circulate depends on how much heat is needed, of course, but it should. This depends on the thermostats. The old Honeywell dials should do that -- but it may help, oddly, to lower the water temperature going to the baseboards from the boilers, so they would have to run longer to keep the house warm. How low? Now that's a bit of a guessing game, but when the temperature is at, say, 20 in your area I'd want them running about half the time at least.

What is the make and model of your boilers? It's probable, given the age, that they aren't condensing -- so the lowest return temperature they should see is around 140. This may mean that you need to use what is called "primary/secondary" plumbing, in which there is a loop which circulates through the boilers, and a different loop which circulates through the heating. That second loop uses a mixing valve to take some of the return water from the radiators and mix it with the supply from the boiler to get the temperature of water in the radiators where you want it.

And the last comment I'll have right now is to make sure that the air is out of the system so it can circulate, and that the system pressure is adequate. You want, for the second floor, about 15 psi as a minimum. Again some pictures will help here.

Ironman

The most common cause of heating pipes freezing and bursting is that they’re run through an unheated space and not insulated. Add to that the fact that you have two zones and heat rises from the lower floor to the upper which keeps that thermostat satisfied, and the water in the pipes isn’t flowing for extended periods, and you have the cause of the failure.

Glycol would be a good choice in your situation, but it has to be mixed to the proper percentage (about 35%) and checked with a refractometer. It also has to be pumped in. It’s not a DIY project.

Also, insulating the pipes in any unconditioned areas and leaving the upper thermostat set about 5-10* higher than the lower one.

Turning the thermostats down and putting electric heaters in the basement is the worst possible thing that you could do.

Also, draining the system for the winter is not a good idea as water will lay in any pipes that are not sloped back towards the boiler and the freeze and break.

psb75

Jaime is advocating that you should "get the air out." Boiler system water should be greatly "deprived" of oxygen--and it is like all heated water--less dense. Unfortunately, it is more "prepared" to freeze! "Heat" keeps it from freezing and so does "movement." You can change this "ready and waiting to freeze" scenario by ADDING GLYCOL to change the nature of the the boiler system fluid. You must maintain a certain percentage of glycol in the system. You must monitor the PH of the system. Glycol is not as effective at transferring heat and it is not as easy for the circulators to circulate as "plain" water. It is not as easy to remove air bubbles from it. There are quite a few trade-offs with glycol. I'm not a big fan of the stuff. You can tell.

hot_rod

A brick house with no insulation will be tough on exterior wall baseboard. The heaters on interior wall may have been a better choice.
Glycol is your best option, both for current problems and also extended power outages.

The system should be cleaned and flushed first. You can buy cleaners that squirt into the boiler from an aerosol can.

Assuming the system is leak free, add a 40% propylene based hydronic glycol. You will need to check the fluid every few years, test kits or strips can be used for that.

If the baseboards are aluminum, use a multi metal glycol. Rhomar is a good brand for cleaners and glycols.

A small pump to put the glycol in. Even a small plastic sump pump from a hardware store will work.

Intplm.

Keeping the heat on and circulating through the zone(s) of your system and adding glycol to the system will lesson the chance of freeze ups/burst pipes.
Adding glycol that is made for a domestic hot water heating system is what you want, and not what is used in your car.

Also as a precaution, adding proper insulation to any suspected problem area is also a good step, but pipe insulation and building insulation are two different animals.
Did you insulate around the pipes with insulation that is house insulation? leaving enough room around the insulation so that it will trap air and therefore work properly or is it stuffed and crushed? Did you only use pipe insulation fitted to and on the pipes? Are the pipes that are bursting installed near an eave or other singular cold area? I suspect that they are, as cold air has a funny way of finding pipes.

As to adding glycol and purging the system? There should be a purge set up at each zone hopefully on the return piping of your boiler. This is a common place for removing water and adding glycol. Adding water to the boiler is also going to be in a similar location.

Pictures of your boiler and boiler piping near and around the boiler at different angles posted here would help.

Daveinscranton

Agree with the above.

You could add a timer to flip on when away etc.   Idea being 2-3 minutes of water circulation every 15 minutes regardless of heat call.  Not hard.  (Famous last words).

Getting to the root of the problem and solving it is better.

Jamie Hall

psb75 said:

Jaime is advocating that you should "get the air out." Boiler system water should be greatly "deprived" of oxygen--and it is like all heated water--less dense. Unfortunately, it is more "prepared" to freeze! "Heat" keeps it from freezing and so does "movement." You can change this "ready and waiting to freeze" scenario by ADDING GLYCOL to change the nature of the the boiler system fluid. You must maintain a certain percentage of glycol in the system. You must monitor the PH of the system. Glycol is not as effective at transferring heat and it is not as easy for the circulators to circulate as "plain" water. It is not as easy to remove air bubbles from it. There are quite a few trade-offs with glycol. I'm not a big fan of the stuff. You can tell.

By "get the air out", @psb75 , I meant -- as should have been obvious, but perhaps not, to make sure the system is thoroughly purged. Nothing like an air lock to slow circulation. The notion that hot water is more prepared to freeze than some other water is, to be blunt, pure nonsense.

A good air removal device will keep the air out of a glycol system quite effectively. That is not a problem, unless there are leaks and you are adding water to the system regularly.

I agree that glycol in a system makes it hard to work on. It also has slightly reduced heat capacity than pure water, and slightly reduced heat transfer characteristics. It also, however, reduces the freezing point of the solution -- properly mixed, to around -30 or lower. This is the objective of the exercise (in liquid cooled engines, both that and the fact that it rasises the boiling point are advantages).

All that said, if one is dealing with a heating system in a house in an area which can get below freezing, you have four choices: either you put antifreeze (glycol) in the system, or you have a reliable person check the house every single day when the temperature is below freezing, or you drain the system for the winter, or you pay for the water damage when a pipe freezes. Take your pick.

zarkbuilder

OP >> Thank you for the feedback which has been helpful in making progress. All comments were read and we appreciate everyone of them. it has taken us awhile to get to this point.

Main Question: If house is empty this winter, what is the danger of completely shutting off the radiant heat system? This shut off would include water, electric and natural gas. Our idea would be to run a small electric heater set as low as possible in the unfinished (raw) basement to keep a small amount of heat in the building. In the boiler room, everything is bare and there is nothing that is flammable except the wooden floor boards with the ceiling above. 'Heat' would vent to two upper floors. But, I dont think a tiny heater on the rock floor could damage the ceiling. The basement is so cool that the heater would not overheat until maybe next june. Your thoughts appreciated.

Some answers for you: basement copper pipes wrapped with the compressed styrofoam stuff that 'snaps' on. a couple 'transit' vertical pipes that are exposed on first floor (leading to second floor) also wrapped same. On a sunny winter day, the top floor can get warm on its own, but the bursts are on the shade end of house, that gets little sun. many comments about ways of bursting and purging are correct (of course) and difficult to read now. Grandma trusted the original plumbers a bitmuch, but also she was living there fulltime. different scenario now.

Diagnosis update: We hired a small size company (several trucks) to send a Radiant heat knowledgeable plumber to diagnose some of the problems. he said that the leak area had multiple welds probably over many years. He would recommend replacing the whole wall unit (radiant pipe with fins and shield) so that there are no 'uncertain' welds to worry about. Also, said that this particular pipe is very close to the wall and, correct, there is no insulation between wall and pipe. If the system (radiant water) is not running (flowing) constantly, then water in this small area can freeze while the rest of the house is warm. I asked about the Glycol (anti-freeze): he said that our system is designed to burn off (steam-off?) water. When relative was living full-time, they could top off the system. For part-time living or winter hibernation, he said the glycol would dilute as new water is added to the system and the glycol effect would disappear in 3- 5 days. Back to freezing risk. He said draining the upper floor system is possible while running the separate main floor system. He agreed that radiant heat for full-time living with the variables this house has, is the most efficient. But , for part-time use, he would recommend changing the whole system to something modern that can be shut off without damage. An intermediate step would be to run an instant hot water system (no traditional boiler) connected to radiant (I think). If no one would be there for long periods, we drain the whole system (except tank). Either the intermediate step or full step are very expensive. We are not ready to make that decision yet.

For now, looking for advice and risks on draining the whole system for the winter. A simple way I look at it is this: If the system is drained, the amount of water that can freeze and leak is very limited. Thus, damage would be limited. We know that the house is made of brick, plaster and wood (mostly planks, not many modern-style floor boards.) See my original post at the beginning for details. Again, the elder family thanks you, its been a rough medical year.

DCContrarian

If you're going to shut off the system you need to either drain it completely or fill it with glycol mix.

You also need to drain all of the other plumbing.

I say "drain" but really to get all of the water out you need to blow through the pipes with compressed air. All of the traps need to be filled with RV antifreeze.

I have two houses in New England that I close down for the winter. The heating systems have glycol and I drain the pipes. With an unoccupied house that's the most reliable thing to do.

Jamie Hall

The plumber said the system is intended to "steam off" water? Ah… no. A hot water heating system should ideally never need to be topped off — it's a closed system. The only exception to that is some very old systems which had a vented tank in the attic, to maintain pressure — and I doubt that you have that.

As I said before, and as @DCContrarian said, you really only have three viable options: keep the place at least vaguely warm with the heating system running normally, drain and fill with a glycol mix, or drain. That one area you mention suggests very much to me that either drain completely or use a glycol mix are the only two good options.

In the meantime, does the system actually lose water? If so, find out why — and fix it. It shouldn't.

DCContrarian

OK, I missed this:

"I asked about the Glycol (anti-freeze): he said that our system is designed to burn off (steam-off?) water. When relative was living full-time, they could top off the system. For part-time living or winter hibernation, he said the glycol would dilute as new water is added to the system and the glycol effect would disappear in 3- 5 days. "

If this is true the system isn't working as designed, it's leaking badly. If it would turn over all of the fluid in the system in 3-5 days then it's got to be leaking something like a gallon an hour. If the house water is turned off while you're away it would quickly run dry and stop providing heat.

This isn't normal and it's not good. Chronic leaking will cause your boiler to fail sooner. Wherever that water is leaking to, the water can't be good for it either. And you really don't want to leave the water on and the system unattended, little leaks have a way of turning into big leaks.

If the leak can't be fixed you need to be thinking about draining the system and shutting the house down when nobody is there in the winter. My vote is still for filling the heating system with glycol and draining the water pipes. But that would require finding and fixing the leak.

leonz

Speaking as a homeowner that has had to deal with many plumbing issues like bad installs and…..,.,.,..,on and on:

If it were me, I would find a licensed plumber that works on steam systems to ACTUALLY find the problem with your radiant heating, fix it and be done with it and fill it entirely with cryo-tek non toxic antifreeze which is designed for heating systems.

The only thing that would be needed is to physically remove and separate the water connections from the boiler or boilers.

For all the money you have spent on this already you could have probably had a small overhead steam system installed on the inside walls with a small steam boiler to heat the entire home with extra take offs/piping to add radiators in the future.