Low Pressure in Heating System

Whitehall_Bohs

Hi, my boiler (Ideal Classic SE15FF) is not coming on. I have noticed that the pressure guage is saying I have only under 0.5 bar pressure.

I have open the valve in the hot press to add more water to the system but the pressure is not rising. This valve is on a pipe coming from the main tank in the attic. Should there be a mains feed somewhere? or should my tank feed re-pressurise the system?

JohnnieK

The pressure wont get any higher than it is on the gauge with the type of system you have. The boiler should fire with this pressure. Is the boiler trying to come on and not firing or is it dead completely? You will need to call an RGI to take a look at it.

Whitehall_Bohs

Yes the boiler is trying to come on but not firing.

JohnnieK

With out looking at it, it could be the electrode or pcb. Can you hear a slight clicking noise when you put your ear up to it?

creedp

Sorry for jumping in here but I was wondering if the same applies with UFH and a HP. Mine has recently been installed and is up and running. However, I noticed that the pressure reading in both floors is very low, reading just barely above zero on both manifold guages. Is this normal? I have mentioned it to the installer and he said he will be back to check the system once it has been running for a couple of weeks but that he didn't think there was anything to be concerned with.

Thanks

heinbloed

Creedp asks:

...I noticed that the pressure reading in both floors is very low, reading just barely above zero on both manifold guages. Is this normal?

The pressure before the pump (return) or the pressure after the pump(flow)?



Has the installer comissioned the system, to what pressure the system is designed for?
The pressure MUST be stated in the protocol, what does it say there?
A lack of pressure can significantly reduce the performance/efficiency and life-time of the system.
Running a heating system on less pressure than it is designed for means that guarantees are nilified.

creedp

heinbloed wrote: »

Creedp asks:



The pressure before the pump (return) or the pressure after the pump(flow)?



Has the installer comissioned the system, to what pressure the system is designed for?
The pressure MUST be stated in the protocol, what does it say there?
A lack of pressure can significantly reduce the performance/efficiency and life-time of the system.
Running a heating system on less pressure than it is designed for means that guarantees are nilified.

There you go again asking difficult questions:) Im afraid I haven't done my homework but thanks for the pointers which I will put them to the installer. At present all I know is the UFH was pressure tested to 5 bar and prior to the pouring of screed (a week) it had dropped to 3. The guages I referred to are located on the manifolds on each floor but as I am technically inept I don't know if they are on the flow or return side. However, the red line seems to be optimistically set at 4 bar so a pretty save margin of safety there! I did note, however, that when the heating was on there seemed to be bubbles in the water as it circulated which created a popping sound as they passed through manifold. Does this mean there is air in the system? I presume that's not good and would require flushing?

heinbloed

Does this mean there is air in the system? I presume that's not good and would require flushing?

Yes.Yes. No.

Topping up of the pressure is demanded. Each distribution group should be equipped with an air separator at the highest point. This avoids air being passed on further.

JohnnieK

If it was tested to 5bar it should not have dropped to 3bar. It sounds like a fitting is weeping. Have you noticed any stains in the location of the manifold? It's possible this problem was fixed prior to start up and the problem is on the main flow and return to the manifold. If the contractor said he will come back I'm sure he will. Write down the things you notice because on the day you will forget half of it.

Whitehall_Bohs

JohnnieK wrote: »

With out looking at it, it could be the electrode or pcb. Can you hear a slight clicking noise when you put your ear up to it?

When you turn it on you can hear it clicking once, as if its trying to fire.
After that when you put your ear to it you can hear a electric like humming.

JohnnieK

Is the fan running? Dont mistake this for the pump!