WB Highflow 400

[Rob]

Went to one these today. The HW is fine but no heating. When i arrived the thing had been on all day and pipe work was hot only about 2ft from boiler (convection?)

Got rid of all the heat in the store and tried heating again. It fired up ran continuously but not to rads. So i assume were looking at diverter rather than pump.

WB suggested its more likely a blockage in the tube which creates the PP to open the diverter. Although it was working fine up untill a few days ago.

Gonna go back with diverter as i didnt wanna strip it all down just to check.

Any advice on changing this diverter as well would be great, heard its a bit of pig!

 

[bobbo85]

its a pig of a job, check if its thaat or the actuator on the 400, are you intrested in how i checked the d/valve or have you done that,

 

[Garfeild]

You need decent access to the left hand side of the boiler,to get the side panel off,and to get inside,last one i did had miles of space,would have been a barsteward if not.
Drain the system rather than turning off the isolators,as they leak,ala pump valves.Yes i found out the hard way.
Dont forget to turn off the cold water to boiler.Diverter is only held on with 4 screws,bottom right is a bit of a devil to get to,make sure you have a loooooooong phillips screwdriver.
New valve comes with new o rings make sure you fit em,dont overlook the very thin one in the middle spigot.
Let us know how you got on.

 

[Garfeild]

its a pig of a job, check if its thaat or the actuator on the 400, are you intrested in how i checked the d/valve or have you done that,

Id like to know Bobbo,may come in handy.

 

[ollski]

Its almost always a sludge problem on these.

 

[bobbo85]

Leave on h/w only and put stat on min,it will fire and then go off,then feel the pipe at the top of the valve,it should be cooler than the other 2,then select c/h and put stat right up,if the motor on the d/valve moves to c/h ,feel top pipe again if it stays cooler than other 2 pipes,its jammed and can be a pig of a job

 

[clf-gas]

Give yourself plenty of time on this, hope you have good access

Concur with Ollski, plate HE is a sludge magnet.


Will remember that one Bob.

 

[ChrisR]

Do I remember a filter which blocks, as well??

Should be easy to search on - here's one:
http://www.diynot.com/forums/viewtopic.php?t=77826

One of my tame landlords has one of these, being erratic. I though better of going in there this time and told her to get WB to service the thing.

 

[Rob]

Thanks for the advice chaps but....i bottled it and they got worcester out same day (good service!). Think ill stick this on the boilers to avoid list.