radiant floor heat....noob here - need help - no heat

rfleenor

Hi. I have a radiant floor heat system in the basement. The thermostat down there does engage the system, the pumps on the system seem to be working (they are vibrating and get pretty warm) but the room doesn't warm up at all....left on for a lengthy time. I attached a picture of the manifold, which I have no idea how to operate so I don't know how the flow is....I can attached more pics if necessary. Thanks in advance for any help.
Randy

Brewbeer

How long has it been running? Are the supply and return manifolds getting warm?

hot_rod

looks like you have some good temperature gauges on supply and return, what do they read?

rfleenor

Brewbeer, hi. I ran it several hours. The water lines at the manifold didn't seem to warm up.

rfleenor

Hot rod. Hi. Looks like one is just under 120* and the other is 70-80*. The third is 70*....by the round gauge.....which shows no pressure....thanks for taking the time to correspond.

rfleenor

Also, will in"feel" water flow at the manifolds? I don't feel any vibrations.

Simply Rad

Well the system needs pressure to operate correctly. The pressure should be around 15psi(depending on system temps). You have a heat exchanger (the metal rectangle in between the temp gauges with the red round sticker on it) in the system so you may have glycol on one side of it. Is the heat source in a cold space or the radiant? Glycol is a freeze protection fluid and the heat exchanger separates it from typically water. Glycol is very viscous and can be smelly. Slowly open the lower drain on the left side of the heat exchanger and see if it is glycol. If so you will need to call a heating contractor. First I would check the glycol
PH level and freeze protection level. And then either add inhibitors or flush the system and install new glycol.

rfleenor

When you say heat source, what do you mean? The what heaters are inside.

rfleenor

Drained. Here it is. Smells. Black.

hot_rod

Yeah, I'm not sure why the heat exchanger? Typically you do not find glycol in a basement radiant. It looks like a high head bronze pump on the other side of the HX, what type of boiler or heat source do you have?

No pressure could indicate a leak. if enough fluid leaks out you could have ann air lock. 4 loops of 1/2" pex, you should have plenty of pumping power.

Brewbeer

@rfleenor, the low system pressure could be an issue. Can you post more photos (from further back so we can see everything)? How water is added to the system? Also, check for warm water on the manifold sides of the flat plate heat exchanger by feeling the pipes. Are both (supply and return) manifolds cool/same temperature? A high mass concrete slab system could take more than several hours to warm up. Is the plate heat exchanger there because the radiant side is non O2 barrier piping?

rfleenor

Yes...hang on. The supply is warm...pretty much always, even if the thermostat is shut off. Like 90* to 120* The return line is cooler.

In terms of the heat exchanger question..I don't know.

We have geothermal heat for the rest of the house...there are two water heaters there as well.I will snap some pics.

rfleenor

Let me know if ya need more.

Will the water lines at the manifold get warm if it is flowing correctly?

Simply Rad

What is the temp gauge reading to the right of the HX(heat exchanger)? R both water heater connecting to the heating? The HX is there maybe to separate heating/drinking water. Not sure why glycol is used in the lower level radiant?

rfleenor

@Simply Rad the temp is about 100* I believe only one heater is connected.

Simply Rad

Last test from me. Turn on tstat for a few minutes then pump you hand on both pumps(red grundfos cans) and make sure they feel way and try and guess if they vibrating. Without service tools its hard to trouble shoot....so.

Brewbeer

@rfleenor, are the manifolds in this photo warm? Cold?

rfleenor

@Brewbeer they are cold...

rfleenor

@Simply Rad both pumps vibrate and get pretty warm, yes.

hot_rod

I assume the system has worked in the past? I would flush that black fluid out and clean the system including the heat exchanger. It looks like the electric water hester feeds the plate heat exchanger, and then heat exchanger (left side) feeds the radiant.

Those plate type heat exchangers will plug from hard water conditions, usually after years of service, and often a gradual decline in performance. Has the heat exchanger ever been serviced?

The manifold ports are all full open, not the issue.

The pump ono the right has a slotted screw head, you can carefully remove that and see if the pump shaft is spinning.

You will need a tankless water heat cleaner kit for the HX and some hydronic cleaner for the hydronic side.

If this is something you want to tackle yourself you will need some specialized tools, purge pump, hose, cleaner chemicals, etc.

Brewbeer

rfleenor said:

@Brewbeer they are cold...

That tells us that water is not circulating in one or both of the loops. When was the last time you observed the floor slab zone to be working correctly?

rfleenor

Thanks all...
We moved in a year ago (winter) it wasn't working then. I'm not sure the last time it was serviced. We've also got well water. I am thinking it may need serviced.....

rick in Alaska

Definitely need to get pressure on the piping feeding it. The circulators will just sit there and spin until you do. If that gauge on top is accurate, you do not have any. Make sure both sides of the heat exchanger have at least 10 psi on the lines.
Rick

Gordy

Good advice from previous posts. I'm with @rick in Alaska get the pressure up see if that helps. Then clean system even if after raising pressure fixes issue.

rfleenor

Okay....updates....the system is loosing pressure...added water, had it back up to 15 psi when operating....and it slowly drops to 10 or lower. I think I have a leak in one of the loops. I'd like to bring it back up to pressure and then close each loop, one a time, and see which one is leaking by watching whether the pressure drops.

My question is how do I shut off the return line valve on the manifold (in pic, one without blue cap)? The supply valve has a blue cap you turn to shut it off. Does this cap come off and be used for the return line to shut it off? See pics.

Thanks all...

Zman

I have not seen that manifold before. Maybe someone here is familiar. My guess is that the blue knob is for balancing and that the other manifold is set up for optional zone actuators. It would be a bit surprising if you could get an older plastic manifold like that to shut off completely and hold pressure.

If you can borrow or rent a thermal imaging camera, you may be able to follow the loops and find the leak that way. You would want to start with a cold slab then watch the floor as it warms up.

The other way to do it would be to replace the manifolds with a model with positive shutoffs on both sides and well as the ability to isolate the manifold and pressurize with air.

rfleenor

Thanks @zman. Do I need to drain the lines prior to installing a new manifold, or just let the pressure out?
Randy

hot_rod

I don't recognize that manifold either, any idea how old it is?

You could buy a bunch of pex ball valves and crimp them into the lines if you don't want to replace the manifolds. About 5 buck each. Then you could isolate a leaking loop if you determine you have one.

Or the SharkBite type valves if you don't have pex crimp tools.

If you are quick they coil be cut and crimped in by just dropping the pressure off

Zman

hot rod said:

I don't recognize that manifold either, any idea how old it is?

You could buy a bunch of pex ball valves and crimp them into the lines if you don't want to replace the manifolds. About 5 buck each. Then you could isolate a leaking loop if you determine you have one.

Or the SharkBite type valves if you don't have pex crimp tools.

If you are quick they coil be cut and crimped in by just dropping the pressure off

This is a good idea and would save a few bucks. How much tubing do you have between the manifold and the floor?
The last time I tried adding valve with a similar manifold, I wiggled the tubing going into the manifold too much and it leaked. I them had to replace the manifold anyway.

If you can move the manifold up and down without stressing anything, I would add the valves. If space is tight, I would replace the manifold.

rick in Alaska

I am pretty sure it is either an older Heat Link manifold or possibly an Infloor manifold. I Haven't used one in quite a while and don't remember exactly the scenario for balancing, but I think you do take the cap off and balance it that way. The top dial is just for show and is just a number to show what it should be balanced to. I will try and see if I can find my old manual and get a better idea of actual adjustment. I am pretty sure both lines can be isolated, however.
Rick

rfleenor

Thanks everyone. I have about a foot from the bottom to the floor, so I probably could get those valves in there. IDK what the pex crimp tool is...

I had someone out to service this (pressurize it) and he mentioned the caps should come off and fit on the bottom....I just couldn't get them off. I didn't want to break them.

To isolate a leak though, I HAVE TO shut the bottom manifold valve off with each corresponding top, correct?