Sime Friendly Format 80e, replaced diverter, rads still hot

[xyralothep]

Boiler: Sime Friendly Format 80e
Problem: Radiators get hot when DHW is run.

I had assumed this was the diverter valve, so ordered a new assy. (part: 6102806) and fitted. But it hasn't really fixed the problem, though it does seem to be marginally better.

When someone has a shower (say, a 10 minute duration) the radiators still get hot. It's as though the diverter valve is only allowing the shower to use some of the heat, and the rest is going round the CH circuit.

Could it be that the new diverter valve I fitted was faulty? Or maybe there is some other part that is causing the fault?

Don't have a manual for this boiler either, which doesn't help!

Thanks, Mike

 

[Agile]

Assuming you have replaced the whole diverter valve then it should have solved the problem.

The back end of the diverter valve is not following the hydraulic unit.

But that problem can be exacerbated if the plate HE is partly blocked.

However if its that badly blocked then it would normally be displaying a hot-cold cycling every 10-15 seconds.

I suggest you remove and clean the plate HE and see if thats blocked.

Tony

 

[xyralothep]

Thanks for the help Tony. I will try as you suggest wrt cleaning the plate HE.

Assuming you have replaced the whole diverter valve then it should have solved the problem.

Yes - I replaced the whole diverter valve.

However if its that badly blocked then it would normally be displaying a hot-cold cycling every 10-15 seconds.

There is no cycling of hot and cold. The DHW flow gives a reasonable shower, but I suspect it could be better if half the heat weren't going round the CH circuit!

What I have noticed is that the problem can be made worse depending on the setting for the DHW flow valve that is built into the diverter valve. This seems to be a feature on these to allow the DHW flow to be reduced if the rising main is too strong (and thus the boiler can't heat the water hot enough). But it has me wondering whether the position of this flow regulator has something major to do with it... but I've spent a while adjusting, without a satisfactory result.

What's the likelihood I've fitted a duff valve, and I need to change it for another?

Mike

 

[Agile]

Not so likely that you have fitted a duff valve if the replacement looked exactly like the one removed.

As its summer and you should not need heating you could close one of the heating valves to stop wasting heat to the rads!

Tony