Ideal FF350 Boiler low pressure & bottom of radiator cold

srteve wrote: »

I have an Ideal Gas Boiler FF350 (serviced September 2013) with pressure gauge and red expansion vessel above the boiler in utility room leading me to figure i have a sealed heating system.

However i also have 3 tanks in my attic, 2 large covered ones and one smaller one next to them, presumably the F&E tanks like an Open Vented System.

Is this a semi-sealed system?

The pressure gauge on my boiler when idle reads just above 0 bar, approx 0.1 Bar and when the boiler is fired up this rises to approx 1 Bar.

I have a vertical radiator that is a new addition to the house replacing an older single panel style one that is not heating up fully. The new vertical rad is a double, 6513BTU/1910Watt radiator that is not heating up at the bottom.

My issue is that this radiator does not get hot, warm at top yes, cold at bottom, but not hot.

I have tried the following to try to remedy this:
- Initially I suspected it may have been air in the system but i understand this in only when there is no heat at the top of the unit. Bleeding with a rad key made no difference as immediate water came out. Suspect this is reason for loss of pressure in system (as per below)
- I tried balancing the radiators across the house but this has made no difference.
- Ive opened all the valves (red wheels) in the hot press to ensure there are no flow issues but this has not led to any improvement in the radiator heat.
- I checked the circulation pump (Grundfos) above boiler to ensure it was on the top setting which it was.

I suspect my issues are either down to lack of pressure in the boiler system or the circulation pump is not powerful enough to pump water to the larger radiator that has been fitted.

I do not have a filling loop that i can open to increase the boiler pressure so i understand that i need to take a hand or foot pump and increase the air in the expansion vessel to the requisite 1 Bar level to increase the boiler pressure.

Is this the advice from the experts here or can anyone else comment on a course of action? I would like to try all avenues before looking to replace the circulation pump.

srteve wrote: »

I have yet to turn off all the other rads except for the new one. If that led to the new one being fully hot how should I open the rest of the rads, I.e in which order?

Where can I find the balance valve? Is this the red wheel valve on the pipe right at the bottom of the cylinder?

srteve wrote: »

Ive done this and it seems to have helped on the new radiator, it did get hotter at the bottom, not quite as hot as the top but as its a large rad i think had i left it for longer it would have eventually.

As for the balancing valve in the hot press, i have two valves there beside each other, one is on a horizontal pipe leading directly into the cylinder, the other is on a vertical pipe upwards from that other pipe.

Ive left the one leading directly into the tank fully open and the vertical one above closed off completely and then opened it just one turn.

Is this valve on the vertical pipe the balancing valve?

Is this the correct thing to do?