Boiler pressure question?

McClane54

Hi everyone

See picture attached, does the dial look right to you? I let some more water into the system about 9months (and was serviced) ago with raised the needle but after that time it seems to have gone down. No obvious leaks etc?? I’m not really clued up in boilers etc

System

I wouldn't worry. All heating systems lose pressure over time due to micro leaks in the piping, joints etc. Most boilers have built in protection so if the pressure falls too low, the boiler will stop working.

Anthorn

I have a Valliant ecoTEC Pro 24 condensing combi boiler which as far as I can see doesn't have a pressure gauge unless it's in the digital readout which I don't touch. The boiler is in a boiler room and the only time I go in there is to read the energy meters. I leave it to the engineer who did the annual service and trust that it is working at peak efficiency.

In conclusion I wonder how important the pressure gauge is in the everyday operation of the boiler and whether the pressure needs to be adjusted by the consumer.

System

Anthorn wrote: »

I have a Valliant ecoTEC Pro 24 condensing combi boiler which as far as I can see doesn't have a pressure gauge unless it's in the digital readout which I don't touch. The boiler is in a boiler room and the only time I go in there is to read the energy meters. I leave it to the engineer who did the annual service and trust that it is working at peak efficiency.

In conclusion I wonder how important the pressure gauge is in the everyday operation of the boiler and whether the pressure needs to be adjusted by the consumer.

According to the installation manual, your boiler does have a pressure gauge - but inside the casing. This is what the manual states:

Quote: To prevent damage to the heating installation caused by low water pressure, the ecoTEC pro is fitted with a water pressure sensor.

If the water pressure falls below 0.08 MPa (0.8 bar), the boiler indicates low pressure by displaying a flashing pressure value.

If the water pressure falls below 0.05 MPa (0.5 bar), the boiler switches off.

The fault message F.22 appears in the display.

> Top up the water and switch the boiler on again.

A flashing pressure value appears on the display until a pressure of 1.1 bar or higher has been reached.

Unquote

Most modern boilers are the same. Topping up the boiler pressure is a simple task that doesn't usually need an engineer.

House_Martin

Mine is ok on 0.7 bar at the moment .It drops sometimes to 0.4 then it shuts down.I turn a switch to put water into the system and increase the water pressure up to 1.1 bar.
I have been told that introducing water into the system is nt good. I think I must have a small pressure leak somewnhere

reeac

Our unvented system needs water added to it occasionally ...maybe 2 or 3 times a year. I suspect that this is due to the air bubble in the top of the Megaflow hot water tank gradually disappearing. This is an accepted fact of life and the tank has instructions on it which tell you how to recreate the bubble. I have carried out this procedure probably 5 or 6 times in 20 years.

System

reeac wrote: »

Our unvented system needs water added to it occasionally ...maybe 2 or 3 times a year. I suspect that this is due to the air bubble in the top of the Megaflow hot water tank gradually disappearing. This is an accepted fact of life and the tank has instructions on it which tell you how to recreate the bubble. I have carried out this procedure probably 5 or 6 times in 20 years.

There is no link between the air bubble in your unvented cylinder and your sealed (unvented) heating system. Heat for the cylinder circulates around a sealed coil inside your Megaflo. If there was a connection between your heating system and HW supply, then you would get rusty hot water as the water in the heating system would continually get replenished. All heating systems leak to a degree as soldered joints, fittings etc expand and contract etc.

matelodave

Most systems run at a pressure of 1 to 1.5bar. A very slow drop, say over a period of several months is probably acceptable. Mine takes around a year to drop from 1.5bar to about 1.2bar, that's when I repressurise it.

Mine has dropped fairly rapidly a couple of times (from 1.5 down to 1 bar in a couple of weeks) and this has been because the auto-air bleed fitted in the heating unit has started to weep - they are easy to replace for about £15.

It's worthwhile having a look around the system to see if theres any sign of weeping in the top of your boiler or at any joints in the system especially around radiator valves etc.

McClane54

Thank you for all your replies

AndyPK

best thing is to wait for the boiler to be cool.

then check to see if its in the green area on 1.

If its below green, add water so its slightly in the green.
When it heats up, pressure will rise, and you want to keep it in the green

reeac

Hengus wrote: »

There is no link between the air bubble in your unvented cylinder and your sealed (unvented) heating system. Heat for the cylinder circulates around a sealed coil inside your Megaflo. If there was a connection between your heating system and HW supply, then you would get rusty hot water as the water in the heating system would continually get replenished. All heating systems leak to a degree as soldered joints, fittings etc expand and contract etc.

Oops, you're right. I should have twigged that from the fact that you empty the tank by turning off the mains water supply and opening the nearest/biggest/lowest tap in the bathroom.