Silly questions!

[heatservice]

Me again I’ve noticed over the past week that when the boiler is cold it is sitting just below 1 and then when working full pelt is getting to just below 1.5 ( this was the pressure the installer left it at when he installed it) but I’ve also noticed that while it’s on, say the 6-9 slot, once the water and room is up to temp the boiler switches off which is right but then when it comes back on the pressure may be back to just over the 1 is this right or should it be holding the just below 1.5 pressure for the duration of the 6-9 period?

Hi, the pressure rise and fall is down to the expansion of the system water, as it heats up it expands more, most of this expansion is absorbed by the expansion vessel, if the pressure starts to go much higher than 2 bar its probably an indication that the air pressure in the expansion vessel is getting too low and needs to be checked. When your pump starts & stops can often cause the pressure gauge to jump.

 

[Lgt88]

So it’s totally normal for the boiler to drop back to 1 when the water in the boiler, or water coming back from the radiators, cools?

Thankfully it’s never gone near 2, always stays below 1.5

 

[heatservice]

So it’s totally normal for the boiler to drop back to 1 when the water in the boiler, or water coming back from the radiators, cools?

Thankfully it’s never gone near 2, always stays below 1.5

1 to 1.2 bar is normal when cold, if pressure drops below 1 it needs topping up this should happen no more than once or twice a year unless you need to bleed your rads excessively.

 

[Lgt88]

Mine seems to be sitting just below 1 when cold or on starting up?

 

[heatservice]

Mine seems to be sitting just below 1 when cold or on starting up?

Many boilers will lock out if the pressure drops below 0.8 bar so it might be a good idea to top yours up to 1.2 (when cold) using the filling loop.

 

[fixitflav]

I have the temp on the boiler itself set at 63 my question is if the boiler itself reaches the 63 does it cut off even if the room isn’t up to the 18 set on the thermostat?

Yes, but it should re-fire at a lower flow temperature, and cycle on and off till the roomstat is satisfied. But see below.

Ok so I turned the boiler temp to 70 which has made a difference with regard to the rooms heating up etc but have noticed that it can drop to around 40 and not kick back in even if room isn’t at temp, so before it got to 18 but I was still a bit cold so I put the thermostat to 19 and the heating was still on but the boiler wasn’t coming on even though the message box in hall had the green light on and the boiler itself read 46 I think it was, how low does it have to be before kicking back on?

A drop of 30°C and it still hasn't re-fired is excessive. It's possible the differential on the control-stat can be adjusted, if not it might need replacing.

 

[Lgt88]

Ok so this is what my boiler is sitting at just now, heating went off at 9 came to check it just now and it was sat 1. Then the dishwasher asked for water (connected to hot water feed as y branch didn’t work for us and just leaked everywhere) and this is what it’s sat at? Sometimes when it first starts up it drops to that as well but then it will rise to the just below 1.5 no problem