
Pressure Gauge Heat Line HK B124
The pressure gauge Heat Line HK B124 measures and controls the pressure of the boiler circuit. If it fails, you will notice incorrect readings, which can cause the boiler to lock out due to a false low pressure or not regulate the temperature properly. This gauge is compatible with boilers from the Capriz, Compact, Hydroline, S, Sargon, and Vizo ranges, among others. It is advisable to replace it when you notice that the readings are not accurate or the operation of the boiler is affected.
VAT included
Consult via WhatsAppCompatible Airsol boilers
Manometer. 19 confirmed compatibilities: 25 and 25S.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Airsol 25 | Capriz | Contrasted |
| Airsol 25S | Capriz | Contrasted |
| Airsol 28 | Capriz | Contrasted |
| Airsol C24 | Compact | Contrasted |
| Airsol C28 | Compact | Contrasted |
| Airsol B24 | Hydroline | Contrasted |
| Airsol 20 System | S | Contrasted |
| Airsol 24 Compact | S | Contrasted |
| Airsol 24 System | S | Contrasted |
| Airsol 30 Compact | S | Contrasted |
| Airsol 30 System | S | Contrasted |
| Airsol 18/20S | Sargon | Contrasted |
| Airsol 24 | Sargon | Contrasted |
| Airsol 24S | Sargon | Contrasted |
| Airsol 30 | Sargon | Contrasted |
| Airsol 30S | Sargon | Contrasted |
| Airsol 35 | Sargon | Contrasted |
| Airsol 24 | Vizo | Contrasted |
| Airsol Plus 24 | Vizo | Contrasted |
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
What determines it is not the boiler model, but the reference printed on the part you already have installed.
- 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 and faults that the manometer resolves
The manometer shows the pressure of the boiler circuit. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The manometer shows nothing, the needle is completely stuck at zero.
Cause: The spiral capillary may be bent, crushed, or have lost its internal fluid, which prevents the needle from moving even if there is actual pressure.
Visually check that the capillary is not bent, crushed, or rubbing against other pipes before declaring the part as broken.
- 02
I see a droplet or stain of moisture right on the spiral of the thin tube that comes out of the pressure gauge.
Cause: A leak in the capillary, which is the most fragile part, can gradually empty the measuring chamber.
Dry the area of the capillary, turn on the boiler, and observe for a few minutes to see if the moisture reappears before replacing the part.
- 03
The needle moves but stops right at the red arc, even though I have bled and refilled it properly.
Cause: If the mechanism is jammed, it gets stuck in the red arc instead of reflecting the actual pressure.
Check the actual pressure of the circuit with another reference point if available, and do not force more filling thinking that water is missing.
- 04
Nothing is visible on the dial, the numbers have faded or the glass is broken.
Cause: It is a physical wear of the part, not a pressure fault of the circuit, and it does not explain any fault of the boiler.
Confirm that the issue is only with the reading, damaged dial or glass, and that there are no warnings or lockouts in the boiler due to actual low pressure.
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.
Airsol pressure gauge data sheet
- Brand
- Airsol
- Type of part
- Pressure gauges & aquastats
- Units in stock
- 3 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- 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.
- Pressure scale / range
- 0-4 bar approximately, with red arcs at the ends
- Type of connection
- Spiral capillary










