Central Heating issue

holidayinn

Hi all, I’ve got an old school open vented boiler with cylinder in first floor and 2 tanks in the loft type system.

Shortly after the boiler fires it gets noisy and there’s a lot banging from the pipes directly above the boiler and around the pump, after 30 seconds to a minute boiler goes into standby (light turns flashing red).

Last couple of times this has happened, the boiler has been off for a day or 2 but then restarting it the system seems to work ok. It's been a couple of weeks and started playing up again yesterday.

Plumber thinks its sludge/debris in the pipes – recommends me to move to a combi system; other plumber recommended replace boiler and pump.

No-one really mentioned a flush or clean but not received full quotes yet.

The system is currently running ok, is there a quick fix? could I try an inhibitor? Or is it too late for that?

Grenage

I'd probably start by investigating the pump.  When they start to go they can bang around a bit and take the pipes with them.

We had that sporadically when our pump went.

FreeBear

Probably wouldn't hurt to run the system for a few hours with a flushing agent added. Drain down & refill a couple of times, and then add a corrosion inhibitor on the last refill.

If the boiler is on its last legs, I would suggest looking at replacing it with a heat pump - The likes of Octopus are often quoting comparable (or even cheaper) prices than a gas boiler. Once set up, and on a suitable tariff, it should be cheaper to run too. But not everyone has a suitable spot to site the outdoor unit..