2 quick plumbing questions to make sure on ...

[liverpoolboy]

Just a few quick q's:

You cannot have a hot AND cold feed washing machine/dishawasher with a COMBI BOILER system can you? they need to be cold fed only?

also to tell if my powerhead to my 3 port valve is faulty is this an appropriate way to be 100% sure: i was advised this but i have my doubts!- test for voltage to my cylinder stat call terminal (number 1) with cyl stat turned up and programmer on for hot water. if fine and no hot water then I can take it my 3-port valve is faulty and not switching on the pump and boiler. BUT from what I have learned, the pump and boiler get energised from the cylinder stat calling and not the 3 port mid position valve moving/opening for hot water only? so how can i test/is this advice incorrect??!

 

[seco services]

as you say your pump/boiler takes its live straight from the cyl stat not the valve.
the valve will have nothing to do with hw calling. as no power to the valve it falls to hw anyway.
then your cyl stat calls for heat to boiler/pump

 

[liverpoolboy]

that's exactly what i thought. so how can i test to be 100& sure the valve/powerhead of the valve is faulty? I do have some rads getting warm when hot water only is on... but i have not broken the 3 tee's rule as this system was installed over 20 years ago!!! any help appreciated.

 

[seco services]

is this the actual problem rads are getting hot with only hw on?

 

[liverpoolboy]

yes thats what's happening. i'm thinking maybe the valve head is faulty? but how can i be sure before changing !!

 

[seco services]

how old is the valve ?
does all the heating / hw work otherwise ?
when heating calling for heat only you should hear the motor and valve open ?
if all working and calling for hw only the pipe on the heating side of the valve is getting hot, then the paddle in the bottom of the brass valve is faulty not the actuator.
rubber paddle worn or crud round port stopping it from shutting heating port fully.

 

[liverpoolboy]

hmm yep i hav heard the spindle can become seized. so a whole new valve will be required, means draining down the system and tieing up the f & e float valve arm!!
the valve is i presume about 20 years old, it is a honeywell v4073a (common and best choice i believe). it has a silver casing.

as a long shot could it not be the motor worn/faulty that is preventing the ball/paddle shutting off the heating side when hot water is calling only??

 

[seco services]

yes that is a honeywell valve and you may need to buy the complete unit as the early ones didn't split.
no it won't be the motor as the valve is in the relaxed position when hw only called for.
so if you totally disconnect all the wiring on the valve it falls its relaxed position which is only the hw port open.

 

[liverpoolboy]

that is why the manual lever can be opened in an emergency to allow heating circuit to open if vale spindle sezies up i suppose? thanks for your help. will have to get a new valve. about 60quid!!! o well!!

i did hear that on any motorized valve if the spindle/paddle goes then the whole valve needs replacing anyway - didn't know only older ones had this trouble?


btw, was i correct with my point about the washing machine/dishwasher with a combi?

 

[seco services]

no the lever is for when the motor fails not the spindle if the spindle seizes up nothing works.

if the spindle seizes up on any model you can just change the brass body.
because the actuator comes off but on the early models you couldn't seperate the two.

check your metal top to the valve if it has a raised in dent on the cover at the front it can be seperated.

 

[liverpoolboy]

sorry i am getting a bit confused here!!

yes the manual lever is to open the alve (or in the case of a 3 port mid position valve) to open it up to mid position to allow heating if the motor fails. (also to help drain down the system)

no dent in the cover, so will be draining down tomorrow! would have to drain anyone even if only the brass body needed to be changed so o well!

but i think i may have a different problem to what i explained - still a faulty valve though!: when h/w and heating on it is fine, and when hot water only on fine and also when heating on only it is fine, the trouble starts when h/w and heating are on togther, then when the heating is turned off at the prog. and the h/w only is still on, the heating still stays on (warms up/stays hot)!! is this common? a faulty spindle still or the motor gone?

sorry about this confusion seco, you've been very helpful.

 

[seco services]

yes if the heating then switchs off and hw still on the valve should fall to its relaxed position.
heating shut, hw open.
if after a while the heating pipe from the valve is still red hot the valve is passing.
ITS KNACKERED.

when you remove the valve blow up the pump port and block the hw port you'll find air will escape out the heating port.
ITS KNACKERED.

 

[liverpoolboy]

yep it's knackered !! it has been like it since last winter but wasn't too bad, i mean it wasn't too annoying! going to change it now though.

seco what do you mean blow up the pump port? i know there are ports A B and AB - what's the pump port? what will this achieve???!!! sorry if i sound ignorant here

 

[spacethegas]

hot & cold feed w/machine is fine with combi.

 

[seco services]

pump port is the one the pump feeds the valve from. bottom one.
it will prove the valve was letting by. because when removed from the wiring etc the valve willbe be in the relaxed position.
heating port shut. but in your cass letting by.