baxi wm511 help pump/diverter problem

[Captain.rick]

hi all,

i have a problem case and as im new to all this i could do with a little help.

i got a call out as no heating but hot water works on a pumped y plan set up. checked pump works but its a little/very hot. pipes either side of pump are hot. but no heat reaching radiators. bled radiators no better. boiler switches off after a few minutes via stat and pipes before and after pump go cold but pump stays running and very hot.

1st thoughts are pump not enough uummppff but on setting 3 anyway so cant turn it up.
2nd diverter valve.... problem is....

diverter head cannot be moved manually as there is no spring resistance however when heating turned on the heating sides gets hot. when hot water turned on both the sides get hot.? cannot hear motor valve moving when selecting either so thinking the valve is stuck in "both" position but then why on heating only does the heating side get hot? but hot water does both sides?

i dont want to make myself look stupid at customers house.

my 3rd choice could be a faulty stat (i know diverter is still a problem too) shutting off early but that seems to be new on the boiler

any help would be appreciated. thanks for looking guys and girls

 

[Captain.rick]

Oh the float works so refills itself fine when i bleed it too

I know i will have to replace three port valve but do you guys think it would be best to check pump spins before by iso valves or just drain down and check pump while empty and do 3 port at same time

I wonder if overheat stat could be faulty too so ill check with multimeter first then do the above stuff...

Does that sound like a good plan?

 

[goz666]

Sounds like a faulty diverter to me pal. I normally stick a screwdriver in the pump to see how strong it is, rule of thumb for me is, if I can stop it with a screwdriver quite easily I change it.
I had same problem a few weeks ago and replaced DV head and pump and all was working fine after.

 

[Captain.rick]

Thanks goz im back round there this afternoon ill give it a go and will report back

 

[AWheating]

Do the pump valves work? If not change them when you change the motorised valve so you can change the pump easy if needed.

 

[Captain.rick]

I bought a pump yesterday and havnt taken the case of side so couldn't check the iso valves but yeah ill change them too if they dont work thanks for the tips mate