Flow and return

[brianhudson]

We live in a bungalow and our pipework is under solid floor so we're not completely certain of the flow of the radiators or wether we have a one or two pipe system.We moved in 2 yrs ago so have inherited this system.We have always had some rads very hot,some warm and one cold(furthest away).During the summer we took off and flushed all the rads( they were very sludged),coupled with putting a cleaner in there has been some improvement but not much.
By feeling the trv/lsv pipes there are 3 rads were the lsv is hotter than the trv and that seems to be confirmed by the probable layout.So we are going to replace all the trv's with bidirectional ones.However we have noticed that the pump has been placed on the return pipe just before it enters the boiler and was wondering if this is contributing to our ineffecient rads.
For ref Boiler is Wallstar 12/15
Pump Wilo gold50

 

[uug197h]

As a rule the flow is on the left, the place of the pump depends on the size of the system if its a 7 to 10 rads the plum is more than likely in the right place

 

[tomy]

If he has a "plum " trying to pump the water round then that could be the problem I always use a pump!!!!

 

[ChrisR]

"flow is on the left"?? New one on me!
Sludge wears pumps, and they don't last forever anyway. I'd change it unless you dismantle it and measure the torque/speed/cleanliness, which you might not be able to do. Pump valves block too.

 

[Nige F]

Professor Plumb .with the lead pipe . in the boiler room

 

[pannierstan]

As a rule the flow is on the left

What

But Im right handed. I always put them on the right

Sounds like you might be in luck and have a 2 pipe as one pipes usually have a flow and return of similar temperature as the water doesnt actually flow through the rad but works more on gravity.

 

[brianhudson]

I have drained off the system and replaced all the TRV's with Bidirectional ones.Water was clean from both drain points and although no more was draining off,two rads had water in them.One of them had really dirty water in it.Connected everything up,bled the rads,pump and system and guess what,hardly getting any heat at all.As the pipes are in the floor,do you think when I drained the system all the sludge fell to the bottom. I could put some more sludge remover to move it about or is the solution Power flushing.

 

[holty]

thing is with vented systems, if you dont know what your doing you could be doing more harm than good.a pump on the return isnt uncommon on older system layouts.as for the rule of thumb on the trv, what!

 

[brianhudson]

Thanks Holty,I have since read somewhere else that the pump can be on the return.What do you mean by "as for the rule of thumb on the trv, what!"

 

[bster]

i think he was referring to ugg197's post.

the trvs might be bi-directional, check to see if there are any arrows on the valve body. a single arrowed line means 'one way' (omini-directional)and a double arrowed line means bi-directional (two-way).

 

[pannierstan]

I have drained off the system and replaced all the TRV's with Bidirectional ones.Water was clean from both drain points and although no more was draining off,two rads had water in them.One of them had really dirty water in it.Connected everything up,bled the rads,pump and system and guess what,hardly getting any heat at all.As the pipes are in the floor,do you think when I drained the system all the sludge fell to the bottom. I could put some more sludge remover to move it about or is the solution Power flushing.

You have probably got an airlock now.
Remove the screw from the centre of the pump(you might get a little water out and then wait for a few minutes.