Evening,

I unwittingly opened the drain valve (don’t ask) on my heating system. It’s an oil combi boiler (sealed system), it stopped working due to low pressure so I topped it up to ~1bar as recommended when it was cold and it seemed to,be working ok for the night but the next night the central heating was no longer working. If I run a hot water tap it comes through ok but there is no heat at all in the radiators. I hadn’t bled any when I first topped it up so thought the system might be air locked so I’ve bled both pumps (Central heating and domestic hot water) and all the radiators twice and topped up the water again but still no joy. When the DHW pump is showing as running I feel like I can feel it vibrating but the CH pump doesn’t seem to be when the led saying it is on is lit up. I’ve checked the only fuse on the pcb and its okay and I gave the pump a love tap with a hammer with no success. Its a Grant Vortex I believe…

How would you discover that your central heating isn’t working in July/August?!

Is there a reset procedure on the boiler, might have stored a fault and shut down, especially if there was an airlock that stopped water circulating for a bit.

How would you discover that your central heating isn’t working in July/August?!

Lives in Scotland maybe?

Only reason we’ve not had a fire in is that we’ve an AGA on 24/7

Have you followed any of the trouble shooting guides in the manual ? The grant vortex manual is the bible, it is fairly comprehensive.

Two things i would think a out perhaps trying – 2 man job one on the drain valve the other on the filling loop and open the drain valve , open the filling loop , let the system circulate then close the drain then close the feed when it gets to 1 bar

Then bleed your rads and pump.

Im sceptical of the pump being fubar as it usually throws an error code wobbler if this is the case

Trail rat I’ve gave that a try with no luck. As you say manual is pretty good but for ‘if your hot water is okay but CH isn’t try x,y and z’ Everything checks out okay…

Chances are there’s an airlock caught in one of the internal pipes of the boiler. Have you bled the internal pipe work since you drained and topped up?