Saunier Duval BDR E Bulb Thermostat for Storage Tank Ref. 353.66.0002
Bulb thermostat for accumulator, with MAX/MIN scale marked on the casing. It is mounted on the domestic hot water accumulator and opens or closes the electrical contact according to the water temperature. The replacement requires first confirming the fault of the part through technical diagnosis, even when the domestic hot water always comes out cold, always very hot, or the thermostat does not switch.
- Type of part
- Pressure gauges & aquastats
- Status
- Refurbished
- internal SKU
- SDBDRM
- Warranty
- 1 year
Compatible Saunier Duval boilers
Manometer. A proven compatibility: Duval BDR E.
Verified compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Duval BDR E | Saunier | Verified |
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 it is the part for your boiler
The part reference, model, and equipment revision must be verified against the manufacturer's documentation.
- Find the reference printed on the installed part and check whether it matches the catalogue reference —. If it is not visible, do not identify the part by its shape alone.
- Check the full boiler model on its data plate and look for it in the model associations on this page.
- Compare the connections and physical body with the original part before installation.
- If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.
Symptoms that require diagnosis on the manometer
The manometer shows the pressure of the boiler circuit. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The hot water from the storage tank comes out cold or lukewarm even though the boiler seems to be working fine.
Cause: The bulb does not detect the actual water temperature or the contact does not close, so heat is not requested for the accumulator.
Make sure that the bulb is fully inserted into its sleeve, without hanging down, and that the wheel is not set to the minimum before changing the thermostat.
- 02
The water always comes out very hot and there's no way to regulate it.
Cause: The thermostat contact does not open when the desired temperature is reached, so the system continues to heat.
Move the stop wheel from end to end and check if the cut-off changes; if the water remains equally hot in any position, the thermostat is not switching.
- 03
The storage tank takes a long time to heat up or never reaches the expected temperature.
Cause: A poor connection in the bulb or in the sleeve prevents the heating demand from being transmitted continuously.
Check that the sheath is free of scale on the outside and that the bulb fits snugly without any play before replacing the part.
- 04
You can hear the thermostat click, but the storage tank doesn't start heating.
Cause: The contact makes the mechanical click but does not close electrically, which is typical of a worn thermostat.
Using a multimeter, check the continuity of the contact by turning the dial; if there is no continuity at any point, the thermostat is the culprit.
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.
Saunier Duval pressure gauge datasheet
- Uniclima internal SKU
- SDBDRM
- Brand
- Saunier Duval
- Type of part
- Pressure gauges & aquastats
- Units in stock
- 7 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Part data and available documentation
Contrast the label codes, PCB, and revision with the installed part; they are not necessarily equivalent references.
- Dial scale
- MAX / MIN
Frequently asked questions about the pressure gauge
Does the bulb thermostat of the BDR E indicate the cut-off temperature in degrees?
When should the bulb thermostat of the BDR E storage tank be replaced?
Is this bulb thermostat compatible with boilers other than the Saunier Duval BDR E?
