Runtal and Raditors piped together

4thGenPlumber

I have to pull out a raditor on a 2nd floor and then install a piece of Runtal.

Issue#1 multi Family

Issue#2 Radiator pipes are 2in and 11/2 by the boiler and 1in by this particular radiator.

issue#3 the Runtal is 3/8



Has anyone come across this before? Whether it's a 1 pipe or 2 pipe system. The background is 1 zone. GB 142 45 Buderus Boiler currently handling the existing radiators just fine. I just see a problem with this. Putting a bleeder set up on the feed and return side is no issue it's the restriction down to the 3/8. Plus with the outdoor sensor they all come with I just don't see this heating up.



Love some input pro to pro

Ironman

The main issue...

Is the output of the Runtal the same as the cast iron rad that's being removed? If it's about the same width, I seriously doubt that the Runtal would have more than 1/3rd the capacity of the CI.



Why is the CI being removed? If it's bad, why not get another CI rad with about the same output?

4thGenPlumber

Runtal and radiators together

Were removing it cause there making the room a wet bathroom. It's an existing 6x8 room that will be 3.5x8 the runtal can get wet and not rust. The btus will change of coarse but more concerned with a rust issue considering it's going to be a nice white tile floor. I'm just not to keen on the changing of the pipe size. I've used runtal before with great results. I can't do radiant and the customer does not want electric radiant in the floor. That would be to easy. Thx for responding

Ironman

Another Option

How about using a towel warmer? I don't know if anyone makes one that's not steel, but you'll definitely get rust from water on the exterior of the Runtal; probably at the mounting hardware. I've seen ones that a customer made himself from copper tubing. They looked good after they were painted.



As far as flow: it's gonna be reduced. There's very little head in the old pipes as they were sized for gravity flow. When the water flow enters the 3/8 lines, it's gonna see a lot more resistance and slow down.



It's a shame that the customer wouldn't go for a radiant floor mat; that would have been the best option.

4thGenPlumber

Runtal and radiator together

The customer is one I've had for over 15 years plus there's both architects. So you know how that goes. A towel warmer is a great idea! I know those at least pipe 3/4. The runtal cover will rust good point. I could use a different style heat that has a plastic cover I guess. I just wish he would go with electric radiant so I could be bout out of it but that doesn't help him. So you agree with the restriction of flow? Going from what was 1in to know what is 3/8?will have head loss?

Stekay

Alternative

I have a Buderus 22 just outside of a walk-in shower (no door) for 10 years. I also use it as a towel warmer holder. No rust.

R Mannino

Towel Warmer

I have a Buderus NB, the tappings are 1/2". it's piped in 1/2" off of a 3/4" baseboard loop with a 1/2" bypass (no monoflo tee's). The supply piping is below the towel bar, it heats perfectly. Everybody should have a towel warmer in their bathroom!



FYI the mounting hardware is plastic.

4thGenPlumber

Runtal and radiators

Looks great!!! I will defiantly recommend that as the pipe size is bigger. Try to find a 3/4 warmer. When the remodel happens the return line which comes from the basement (about 20 feet away from the radiator) I'll run 1in copper up in the wall. The feed the same but it's 5 feet away. The runtal is iffy.. Dropping down to 3/8 just doesn't seem like a good idea .



Thank you soo much for wisdom and input !!!!