Towel Warmer Not Heating

Alan (California Radiant) Forbes

Yesterday's schedule started out cleaning a boiler we installed in 2003. The owner was showing us around the house and told us about a towel warmer that has never worked. I took this picture of the rough piping - the supply of one of the floor loops that we brought up the wall for the towel warmer. We installed two diverter tees for the towel warmer. The floor heats fine, so I know there's flow through the loop, but the towel warmer doesn't. Why?

Abracadabra

I'm not a hot water guy, but I'm guessing because the resistance thru the towel warmer is greater than the direct route thru your pipe? Instead of diverting I'd have gone in and out thru the towel warmer. Again, not a hot water guy.

Gordy

Obstruction, air, or resistance in the towel warmer.

Harvey Ramer

It could be air as Gordy suggested, or it could be you have the supply and return reversed at the manifold, reversing the flow through the loop and not allowing the tees to work properly.

Ironman

Is there a flow setter on the towel warmer?

My first though would be that it's air bound since a monoflo loop can be extremely difficult to purge of air.

JUGHNE

I see 1/2" S & R copper with 3/4 between diverter tees. Would the 3/4 loop be the easier flow route than the towel warmer?
Or am I thinking backwards on a Senior Moment?

Copper DWV.....just about never see that here in fly over country.

Solid_Fuel_Man

Are those diverter t's supplied be 1/2 PEX and the 3/4 copper between? May be too little flow with the nice low loss between the two T's. Could it be airborne? Can you power flush that loop while bleeding the towel warmer at the same time? That's what I'd try first. Bleed Bleed Bleed while power purging that particular loop. Btw: great job taking pics for reference 13 years later!

Taylor

JUGHNE

My understanding is that the floor loop goes thru the wall piping we see and that that floor loop heats ok???.....that would seem to mean that that circuit is not air bound....towel warmer maybe but not entire loop.
I wonder if that 3/4 stayed at 1/2 if some flow would go thru the towel warmer.
Choke the 3/4 down a little.......hard to do in a finished house.

FranklinD

Yep...my "mind's eye" sees it as this:

The water comes into the Diverter Tee at 1/2", sees the 3/4" ahead and the 1/2" to the side with all sorts of bends and a towel bar radiator, and sees the 3/4" between the tees as the easier route. I think if you choked it back down to 1/2" between the tees, it might work better.

Just my 2¢...not a pro by any stretch.

JUGHNE

Harvey's idea is a good thought if the tees are backward in reference to the water flow. A non invasive attack could be to reverse the flow at the manifold. Might warm the towels a little.

Gordy

I'm thinking air bound IF diverter tees are correct. Diverted t systems are hard to purge as ironman noted. That towel warmer does not lend itself well to air removal like a baseboard. Gotta pic of the towel warmer?

hot_rod

many of the towel bars have air bleeders on them. If the towel bar has isolation valves on S&R and an air bleeder, you should be able to force air out.

Paul48

All monoflo systems have a looped main. Ever see a radiator run with the supply on one side of the loop, and the return across the basement? I know that's an exaggeration, but that's what you did.

JUGHNE

I think if there was a way to gracefully add a globe/ball/throttling type valve in the left 3/4" copper line that is inside the wall, then the HO could close it for warmer towels and cooler floors or open it a bit for the opposite. Some HO like control of such things.
Not very invasive unless that wall is covered in ceramic tile.

EBEBRATT-Ed

I would suspect the diverter tees are too close together. Maybe you can add some resistance between the tees

Alan (California Radiant) Forbes

The vertical supply and return lines are 1/2".

If we installed the diverter tees correctly, it wouldn't do any good to reverse the flow.

The towel warmer looks like a snake with valves on supply and return. When I was there, I closed the upper valve and loosened the upper union; did the same with the lower valve closed and didn't get any air on either one.

The owner is willing to open the wall and I'd want to inspect the diverter tee installation. If correct, I would add a partition stop between the tees to promote flow and air elimination.

http://www.dahlvalve.com/products/PDFs-catalogs/POM-Mar-PartitionStop.pdf

Thanks for everyone's input! Much appreciated!

Ironman

Got a pic of the towel warmer? The ladder shaped ones that I've done had a dip tube that had to be on the supply to get reverse return flow through it.

Alan (California Radiant) Forbes

Sorry, I don't have a picture of the towel warmer. It's a single pipe, weaving back and forth from supply to return. No air vent, no dip tube.