Recent content by johnkirk

Yes, good point, I could dispense with the existing smart thermostat that's on the hallway wall and use just a smart TRV in the hallway radiator. This would give the same result, as you say. The smart wall thermostat (which I've used for over 2 years before acquiring any smart TRVs) would then...

I have the Tado system with all trvs being smart ones. The wall thermostat in the hallway is Tado's smart thermostat, but the smart TRV which is also in the hallway will not battle with the wall thermostat because I can select the temperature control in the hallway to be dictated by the wall...

This is exactly the current setup, which is unsatisfactory. If this radiator, which is in the hallway, has no smart TRV when all the other rooms have them then it will heat up when one or more of the other radiators is calling for heat, irrespective of the wall thermostat which is also in the...

Bypass pipe length would be about 1.5m long, and need to be routed through awkward angles and restricted space to connect flow to return, hence strong preference for the more flexible and space saving 15mm plastic pipe, rather than 22mm. As for whether I can still obtain the right flow or not...

I'm aware that the copper flow pipe protrudes vertically downwards into the heat exchanger. So to minimise copper attack, to the point that is negligible, only 10% strength HCl would be used, cold, in the heat exchanger alone, and for only 45 mins, then the HE flushed thoroughly and neutralised...

Thanks, Onetap. I'm about to start the descale later this week, and I'll report back on what I've done, and the outcome, soon after.

Thank you Tony, that's a very helpful response.

Tony, in my opening post I'm actually asking if my procedure involving these chemicals is overkill, so you're clearly saying "yes". The reason for wanting to use several chemicals in turn is because no one of them is good at dealing with all the types of unwanted deposit (limescale...

Short term solution that only stores up problems for the future, surely? Washing up liquid contains 20% - 23% salt. Just what my steel radiators need! But thanks for the advice, serious or otherwise! Reminds me of cowboy car mechanics who quieten noisy gearboxes by adding sawdust to the oil.

As far as I can tell, hydrochloric acid has no negative effects on rubber. Hydrochloric acid often comes in plastic (rubber family) containers, and H & S advise on using rubber gloves when handling this acid.

I know there’s a lot of good advice on this forum on this topic, so I’m hoping for any useful comments on the plan below for descaling my cast iron boiler. Thanks in advance! The boiler is Potterton Netaheat Profile 50e, 25 yrs old and, for its first 24 years, never ever had any inhibitors...

Thanks for some helpful responses above. * Yes, sorry, I did mean to say Sulphamic (Sulfamic) Acid, and not sulphamite. * The pump has been raised to the highest of the 3 speeds several times in order to dislodge possible trapped air, and the normal speed is set at the middle one...

Thanks doitall, but that's just what was done during the flushing stage a few months ago. I must now presume there is residual magnetite etc that will always remain. Looks like Spiotech's air remover could be a last resort, but I'll wait a further couple of months.

The cylinder is copper, indirect, about 12 years old.

Perhaps I need to wait longer, into winter, for the system to get much more use. Also, the system volume is quite large, at 105 litres, when pressurised to 2 bar, so maybe I need to wait till mid-December and then re-assess