Poor hw flow from a combi.

[traineedrip]

I have a sime super 90 combi boiler. Hot flow has suddenly decreased, yet cold is fine.

Whats the usual culprit?

[aggis]

Might be a filter on cold inlet to valve. Before you strip it down to look there's a flow adjuster on the outlet of the diaphragm housing, try adjusting, using a 7 or 8 mm spanner. might justbe some crud stuck in it .

[Bill the gasman]

Blocked filter usually

[PlumbingSucks]

been to a few where hw heat exchanger has scaled up especially if no limefighter fitted on the cold supply., Take it out and use Spirit of salts solution which i think is hydroclauric acid. Just fill it up and let it soak for 5mins then wash the crap out and refit. only 20 min job!

[traineedrip]

Thanks all. Problem solved mysteriously by itself a couple of hours later. Looking back i think cold pressure had reduced too but far less than hot, so im putting it down to something external on the main. Boiler is 13 years old so id imagine the filter is choking the hot to some extent.

[fuzzy]

good result then!! keep a clsoe eye on it you have some ideas for future mate

[GPSNewcastle]

been to a few where hw heat exchanger has scaled up especially if no limefighter fitted on the cold supply., Take it out and use Spirit of salts solution which i think is hydroclauric acid. Just fill it up and let it soak for 5mins then wash the crap out and refit. only 20 min job!

You can soak it in vinegar aswell mate (tip I got from an old codger I worked with)

[PlumbingSucks]

Nice tip thanks. Didn't know kim and aggy were plumbers aswell just thought they cleaned houses. LOL