Pressure virtually nil but central heating is working…how ???

[shd1970]

I’ve returned from holiday today and my central heating system (Worcester Greenstar 37cdi) has a leak on my Fernox TF1 joints
I’ve got some rubber washers so will replace tomorrow

But my question is, the pressure needle as shown on the attached photo was virtually nil BUT the central heating was working fine and the radiators were hot

1 - I thought if the pressure was so low that the boiler and central heating wouldn’t work, correct, or gave I dreamt this ?

2- as I had set the heating to come on whilst I was on holiday, has is done any damage running with virtually no pressure in the system, and needing a top up ?

Thanks in advance of anyone able to clarify

 

[CBW]

I think they run as I don’t think they have a low water pressure sensor

 

[Mister Banks]

I’ve returned from holiday today and my central heating system (Worcester Greenstar 37cdi) has a leak on my Fernox TF1 joints
I’ve got some rubber washers so will replace tomorrow

But my question is, the pressure needle as shown on the attached photo was virtually nil BUT the central heating was working fine and the radiators were hot

1 - I thought if the pressure was so low that the boiler and central heating wouldn’t work, correct, or gave I dreamt this ?

2- as I had set the heating to come on whilst I was on holiday, has is done any damage running with virtually no pressure in the system, and needing a top up ?

Thanks in advance of anyone able to clarify

Interesting video about this.........

 

[Johntheo5]

Is error code 1017W only on newer models?

 

[CBW]

Is error code 1017W only on newer models?

I’d say so, as that’s a similar model to the Greenstar junior, which only has fault lights not codes

 

[shd1970]

I think they run as I don’t think they have a low water pressure sensor

Thanks @CBW

So a future project I’m planning to do is add a few more radiators but I was apprehensive about not completing it in a single day and thus we had no hot water either

So do you think I can effectively knock out the heating then but my taps will work fine ?
Hopefully when I get around to it in the new year I can complete it in a day but the wife is nervous shall we say

 

[shd1970]

Interesting video about this.........

Thanks for sharing @Mister Banks

So seems like it will run but damage is being done until eventual failure….agree ?

 

[Johntheo5]

Probably no damage done IMO as you did maybe have ~ a 2M head of water and if the upstairs rads were hot then every chance no damage.

 

[shd1970]

Probably no damage done IMO as you did maybe have ~ a 2M head of water and if the upstairs rads were hot then every chance no damage.

@Johntheo5 …… 2M ??

 

[Johntheo5]

PG is showing, being a little bit optimistic, 0.15/0.2bar, 1.5/2M? that boiler has probably a hi limit stat on the heat exchanger which would/should have locked the boiler out in any case and the water wasn't all lost suddenly like in the case of a pipe coming adrift, that happened to my neighbours OF Firebird and the hi limit stat just shut off power to the boiler.

 

[shd1970]

Thanks @Johntheo5