3-Way Valve with Motor, No. 591958, Thema/Themaclassic Ref. S1020800

Saunier Duval boilers compatible with reference S1020800

3-way valve with reference S1020800. 16 verified compatibilities: ThemaClassic F 24 E and ThemaClassic C 24 E.

Proven compatibility

Can't see your model or have questions? The printed reference takes precedence. How to check it · Send us a photo via WhatsApp.

How to check if ref. S1020800 is the part for your boiler

What determines it is not the boiler model, but the reference printed on the part you already have installed.

1. Find the reference printed on the installed part and check whether it matches the catalogue reference S1020800. If it is not visible, do not identify the part from its shape alone.
2. Check the full boiler model on its data plate and look for it in the model associations on this page.
3. Compare the connections and physical body with the original part before installation.
4. If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.

Symptoms and faults that the S1020800 three-way valve resolves.

The 3-way valve diverts water between heating and domestic hot water. These are the typical symptoms and what to do:

Common symptoms and faults

• 01

  You have domestic hot water but the heating is not working, or vice versa.

  Cause: The internal shutter of the three-way valve gets stuck and does not allow water to flow to the corresponding circuit.

  Check if the gas valve motor turns when requesting domestic hot water or heating (you should hear a clicking or brief buzzing sound) before replacing it.

• 02

  The boiler takes a long time to switch modes or gets stuck halfway between heating and domestic hot water.

  Cause: The motor does not have enough power or the internal mechanism is blocked by scale or dirt and does not complete the rotation.

  Listen for a prolonged straining noise from the motor when switching modes; if it stops halfway through the process, it could be the gas valve.

• 03

  A thump or buzzing sound is heard in the area of the valve every time you request domestic hot water.

  Cause: The motor gear or the return spring are worn out and do not allow for smooth movement.

  Locate if the noise comes from the body of the gas valve and not from the pump or the burner by carefully touching the pipe.

• 04

  The water comes out lukewarm both from the tap and in the radiators at the same time.

  Cause: The shutter does not close completely, allowing a crossover between the two circuits instead of separating them.

  Note that when opening the domestic hot water tap, the radiators cool down a bit; if they do not change, the valve may be mixing.

Fault codes from Saunier Duval that this spare part resolves.

These symptoms can have more than one cause. If your boiler displays a fault code, send it to us via WhatsApp along with a photo of the labeling, and we'll tell you if this is the part.

Data sheet for the Saunier Duval S1020800 three-way valve.

Catalogue reference

S1020800

Brand

Saunier Duval

Type of part

3-way valves

Units in stock

1 unit

Status

Refurbished

Warranty

1 year

Shipping

1-2 business days

Return

14 days

Data read on the part and in the manufacturer's documentation

What we have not been able to verify does not appear here.

Number embedded in the part

591958

Manuals and technical documentation

Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.

• Saunier Duval Themaclassic F 25 E Manual (PDF)Document © Saunier Duval, provided as a technical reference.