Caleffi panel radiator valves

Paul S_3

I cannot get a answer from my Caleffi rep. We will be using about 14 buderus model-21 and model-22 panel radiators on an upcoming job. Can the Caleffi 3010 & 3011 radiator valves be used on these buderus panel radiators. Thanks
@hot rod

hot_rod

I don’t think the Caleffi valves match up to Buderus, but I have not tried one myself

Paul_11

hot rod, since your on this thread I will take advantage.
What size Caleffi would you use for an 16 unit building each with one bathroom. The CW & HW piping is 1 1/4" so line size could make sense, but I am wondering if I can use a 1" which is significantly less expensive to buy.

hot_rod

Paul said:

hot rod, since your on this thread I will take advantage.
What size Caleffi would you use for an 16 unit building each with one bathroom. The CW & HW piping is 1 1/4" so line size could make sense, but I am wondering if I can use a 1" which is significantly less expensive to buy.

A zone valve size?

Paul_11

hot rod, sorry for not being clear. Domestic hot water mixing valve.

Paul S_3

I was told that the Caleffi valves can be used on the buderus radiators.... I contacted Caleffi through Instagram (@caleffi_na) and they told me I can use them.....was this information wrong that was given to me?

hot_rod

Usually on a building like that you want a hi-low. The small valve will regulate accurate down to a 1 gpm flow, as more load comes on line the PRV diverts to the larger valve rated to 50 gpm.

You could also put 2 small, maybe 3/4 or 1" valves in parallel.

Ideally you would calculate max. flow rate for the building, adding FU fixture units for each apt. Then you could select the best option.

Most of the water heater manufacturers have DHW sizing tables based on the building type and use.

We also have an EMV, electronic mixing valve coming out. It covers a wide GPM range and can be actuated for anti legionella function and data log.

If you use just one large valve, say an 1-1/2 or 2" it will not mix accurately at low flows, below 5 gpm for example. The valve will "hunt" and you get weird temperature fluctuations.

Day_Knight_Plumber

Hoping to contribute to this valuable resource with some of my recent learnings related to threads and european radiators as part of a home remodel project involving a hydronic heating system. I am not a plumber but a keen interest for the trade, a DIYer with education in physics, thermodynamics etc

Background: I live in a 1930's home in MA, and as part of a major remodel have installed a new subfloor and flooring. This included a fair amount of leveling. The house has an updated heating system (which I am gradually expanding and improving). The floor being remodeled has a system of euro-style panel radiators (models 21, 22), installation is a 2 pipe home -run (2 zones for first floor) using 1/2 pex (Uponor hepex), with shutoffs at the manifold. System is 1 year old as is boiler, a high efficiency german machine. Euro panel radiators need a clearance of 4in from the floor.

The main issue that brought rise to all this was that the radiator piping was too short with new floor. I tried mounting radiators with the existing / prior connections when clearance was only 2" inches but it seemed too difficult to be right even how the threads tied in so I researched further. (the radiators were disconnected by the floor installer)

Here are additional issues I had to resolve:

- I wanted shutoff valves at each radiator. these valves are specifically designed and are also known as Eurocon H Valves. they add 2-2;5 inches height. Most of my radiators were directly piped which is perfectly ok had they used the correct threads.
- whilst dealing with this I realized that the original installers totally screwed up with the whole thread situation. The used incompatible threads and used pipe goo to seal everything up.
Further investigation and questions at various plumbing outlets, H valve suppliers, Radiator Suppliers/Manufacturers revealed that these things are usually sold in complete packages. There is not much information about threads and compatibility. All that takes is a missing nut on a job and the genius misinformed idea of using an uponor or propex fitting with a NPT thread.

Summary: NPT US threaded fittings should not be used with Panel Radiators (or most hydronic manifold connections). Garden hose threads are also incompatible.
Details of the connection(s) are as follows:
- A Euro Style panel radiator (various manufacturers, pretty standard connections) connects via a 2 pipe system (2 " distance off center). The radiator itself usually has 2 Female (ports) which are 1/2" parallel threads also known as G threads (the nominal metric (din) equivalent to 1/2" is 15mm ie G15+G1/2)

The panel radiators usually connect to the system via an adapter. This is usually a provided brass nipple with a G15 Male thread fitting for the radiator. The other end of the nipple is a 3/4" R Thread.
(R threads are also known as Tapered and BSPT. As with 1/2, the nominal size can be expressed as 3/4 "or 20 mm)

The R 3/4 nipple is designed to connect directly to the piping or to an isolation valve using an EK20 (Female) connector. An EK connector uses R20 threads however the fitting uses a swivel nut and the insert contains an O ring that seals the connection. Most of these connectors are only available as compression (and maybe sweat for copper). TIP: Incidentally many hydronic heating manifolds use EK20 parts and the same identical connector can be bought for 1/4 of the price if you shop in the manifold aisle/section

SUMMARY OF CONNECTIONS (all connections are 2x supply/return)

RADIATOR= 15mm G thread F
Nipple= 15mm G thread M to 20mm R thread M
H Valve = EK20 connection F to 20mm R thread M
Pex to system = EK20 compression fitting F
NOTE: NPT and garden hose ie Common fittings found in the US are not compatible and should not be used. Do not try or you'll regret it.
These fitting seal by means of a gasket so brute force and thread goo are not needed.

Note: Thread compatibility gets complex but in theory a G1/2-G15 parallel thread male fits into a equivalent size R thread Female (aka port). The issue is that usually R threads seal using a gasket and using the parallel thread will mean that the seal will happen at the threads ie you need pipe goo... this is not how the system was designed, its not optimal but it could work for a low pressure system. Unless you source directly from europe, forget propress, uponor fittings for the connections at the radiator ends they are all going to be NPT threads although you do fine R20 Femal connections (not EK20 seal type though so not ideal ... see pipe goo note above ) . Compression exist for all the various pipe types and sizes. They should not be overtightened.


Summary:
BSPT = R threads = Tapered
BSPP = G threads = parallel threads
NPT / US FITTINGS ARE NOT COMPATIBLE


Hope the above information is useful.