Boiler operation; cold zone; SolaRoll installation

Lee_Harris

We just moved into a Taos, NM home: adobe construction with tile floors. Originally built in 1992 with SolaRoll radiant heat in 2 zones. A 3rd zone was added a few years later (presumably still SolaRoll, but not confirmed). Reportedly the house was unoccupied, but (presumably) heated to some extent in the winter) for the last 5 years. When we moved in 11 days ago, the interior temps were just above 50F. Night temps around here are generally in the teens, daytime 30's - 40's.

The house also has a solar-water system for DHW and to supplement the boiler heat via a heat exchanger. The system is configured with an outside temp sensor.

Turned the thermostats up to around 68F when we moved in.

Problem: The 3rd zone is still cold; the floor tiles don't seem to have warmed up at all. Zones 1 and 2 have finally warmed up to mid-60's, but still not to the set temperatures. I have verified that the zone valves open and close properly - they're only a year or two old.

I've been observing the system closely ever since we moved in. I think the boiler generally fires for 10-20 seconds a few times an hour. Up until a few days ago, it would only fire up to around 110 degrees. In the last couple days it's been going up to 130 and I see the output-to-floor temperature sometimes up to 120. I'm concerned about stressing the fairly old SolaRoll tubing in the floor.

The output-to-flooring temperature varies from 90F to as much as 120F (when the boiler output has gone up to 130f).

Questions: Should this boiler be switching on and off so often, rather than just heating at a low enough level to maintain consistent boiler output temperature?

What would be the highest recommended output-to-floor temperature and pressure for this installation in view of the age of the SolaRoll?

What's the best/easiest way to verify flow rates on the individual zones - perhaps the #3 zone isn't getting enough flow? The floor-return temp is up to 67F, so there's been a pretty consistent drop of about 30 degrees, but that's across all 3 zones. If I restrict float to just the one 'cold' zone, and got a smaller temperature drop, would that suggest inadequate flow for that zone?

Thanks for any observations/recommendations...

Jolly Bodger

It sounds like there are a couple issues going on there. The boiler shout defiantly be running longer. And you should be able to get some steady supply temps. Though if an outdoor reset is in play that will track the changes in temp.

Probably also have flow issues. This may be compounding the boiler short cycling. Some pictures of the system, boiler model and controls type and pumps, would help.

Paul Pollets

Solaroll has a 1/4" diameter and is subject to sludging over the years. The loops farthest away from the boiler often become the depository of the sludge, which can harden and greatly restrict or stop the flow. Cleaning can be difficult and requires great patience, and often an air compressor to blow out the loops. A strong cleaner can be pumped in and left for several days to circulate before flushing, refilling and purging.

hot_rod

I agree with Paul, sounds like some sludges loops. Often times you need to remove every loop and test for flow

Does it hold pressure? It can split if it froze

zimmie1

I also have SolaRoll radiant heat going back to 1993. I was told to scrap the system. Should I try the method Paul recommended?

hot_rod

They were a unique manifold, once you remove the tube from the manifold I doubt you get them back on,

Here is what the inside look like. A small nylon sleeve went inside the tube before you push it in, one in, they don't pull out. But they could leak

I remove all the tube from the two manifolds. Then use an air nozzle with the compressor to see which are still usable.

But now you need to build a new manifold.

Solder 1/4" copper tube into a piece of 1" copper and use plastic automotive ratchet clamps to clamp the tube over the 1/4 copper branches. If you want a barb connection find small brass barb adapters at a welding supply, same size is used on Oxy/ Acetylene hose connections.

I doubt many knowledgable contractors would take it on, or guarantee the work.

I would consider a plan B.

Renew_Rest

Hi guys! Same boat here with the Sola Roll. I have a place in Taos as well with a lovely project ahead. A plumber had air pressure tested it last year and they said it seemed to hold. But this is a challenge I’m going to have to try and tackle as Im not going to pay them $125/hr to scratch their heads. 😂 

The old Teledyne-Lars boiler has been removed and I will take it out and attempt to inspect, and post pictures, if I find it in the garage. 🤞

I would like to learn how to blow them out with the compressor and how to flush them properly (what type of machine), and if there is a cleaning agent, which one will not degrade epdm?

I’m currently working on the water from the well (testing,filters,ph) and have been deciding on a tankless heater that handles radiant heat as well. Any comments?

*What air pressure psi should I use for the dry test? *What water pressure and temp should the lines have?
*What type of pressure reducer is applicable?

Figured I would have to build a new manifold and replace pipes with the copper corroding. 

Newer to mechanicals and really want to see if this system will potentially still work, for the challenge of it all. 😀

Thank you all in advance! I’m so grateful to have found you here on this site! 😎 

Jamie Hall

The one thing that jumps out... don't, please, use a tankless heater for the radiant. They are built for short runs heating domestic hot water, not long runs heating a slab. And it will be too big. Figure out how much your radiant floor can put out, and size a proper heating boiler to that.

mattmia2

Was that stuff like zip cord, 2 tubes bonded together and you connected them at the end to form a loop? It looks like it is coming out of the floor in bonded pairs.

Zman

How brittle does the tubing feel? Is there rubber debris in the circulator or air eliminator (yellow cylinder)?

Before you start, you will want to have a clear idea of what "plan B" looks like. Is it possible to snake 1/2" tubing to each room and install a panel radiator? https://runtalnorthamerica.com/residential-radiators/

If I were betting, I would bet against a system like that performing well in the long run.

Paul Pollets

Most of the Solaroll systems I worked on were filled with sludge in the tubes and the sludge was difficult, if not impossible to remove. The sludge hardened and prevented water flow, even with boiler cleaner chemicals and pressurizing the loops with air. The cast iron boilers were also damaged by extreme interior oxidation and "iron mud" at the bottom of the boiler. The solution was to abandon the radiant and install wall panel radiators.