Viessmann Boiler 7834985 Pressure Gauge

The Viessmann pressure gauge 7834985 monitors boiler pressure clearly and accurately in compatible Viessmann boilers. As a result, it helps support safe, efficient, and reliable heating performance. However, if the gauge becomes faulty, damaged, or difficult to read, pressure checks can become less accurate and boiler operation may suffer. Therefore, replacing it helps restore clear pressure monitoring, improve system control, and keep the boiler running smoothly.

Compatibility :

• 100 WB1C Combi: 26kW, 30kW, 35kW
• 100 WBP JA Combi: 25kW, 29kW
• 100-W WB1B Combi: 26kW, 30kW, 35kW
• 100-W WB1B System: 26kW, 30kW, 35kW
• 100-W WB1C Combi: 30kW

Important fitting advice

We recommend that all parts are fitted by a fully qualified Gas Safe registered engineer. If you need help confirming the right part, contact us our team has 10+ years of boiler spares knowledge and friendly chat support to help you quickly.

Delivery

At Boiler Spares Hub, we dispatch orders within 1 working day (Monday-Friday). Orders placed outside working days will be dispatched on the next working day. For delivery options available for this product, please add it to your basket or check our delivery options page.

Returns

We accept 30-day returns. Returns must be in an unopened, sealed box. If we find the item has been used or installation was attempted, we may refuse the return.

Frequently Asked Questions (FAQs)

1. What does a pressure gauge do in a boiler?
A pressure gauge shows the current water pressure inside the boiler and heating system.
As a result, it helps you check whether the system is running within the correct pressure range.

2. What happens if the boiler pressure gauge is faulty?
A faulty gauge can give unclear or incorrect readings, which makes pressure checks more difficult.
Therefore, it may become harder to spot low or high pressure problems before they affect performance.

3. Is Viessmann pressure gauge 7834985 compatible with my boiler?
This part fits selected Viessmann 100 and 100-W combi and system boilers listed in the compatibility section.
However, you should still match the manufacturer code 7834985 and your appliance details before ordering.

4. Why would a pressure gauge need replacing?
Over time, the gauge can become damaged, worn, or difficult to read clearly.
Because of that, replacing it helps restore accurate monitoring and improve day-to-day boiler checks.

5. Can a faulty pressure gauge affect boiler performance?
Yes, because inaccurate readings can make it harder to identify pressure-related faults early.
Consequently, unresolved pressure issues may lead to poor heating performance or system interruptions.