Central Heating circulation issue

[egizz983]

Hello i recently converted heating system from old stove to grand vortex b house 90 , boiler runs and works fine . How ever i have issue with water circulation have installed new pump but for some reason water don't circulate at all . what are the possible cause ? i have pump installed on return and and have one way valve on coil return I have attached image on how it looks like and schematics

 

[ShaunCorbs]

Pump installed in the wrong place also shouldn’t be facing up the bleed screw needs to be on the side or at worst 45 degrees

 

[egizz983]

move next to the boiler ? i left here as it was here before , and it was more convenient for electrician to connect all

 

[ShaunCorbs]

After the cylinder but your feed and vent arnt in the best position most likely will pump over

 

[egizz983]

After the cylinder but your feed and vent arnt in the best position most likely will pump over

you mean on the other side of the T ? where should went be located then ?

 

[ShaunCorbs]

As per my image also best to upgrade to an s plan from a gravity set up also while your at it eg port valves

 

[John.g]

How is the water pumped through the cylinder coil?

 

[egizz983]

As per my image also best to upgrade to an s plan from a gravity set up also while your at it eg port valves

based on that image would be best to put that pump on flow right after vent pipe pumping downwards ?

 

[ShaunCorbs]

So in the picture the right are the pipes straight from the boiler ?

 

[egizz983]

So in the picture the right are the pipes straight from the boiler ?

no two pipes on the left traight from the boiler . pipes on the right is from attic

 

[ShaunCorbs]

So the left out the floor is the boiler ones
The ones on the right are to your rads ?

 

[egizz983]

So the left out the floor is the boiler ones
The ones on the right are to your rads ?

yes correct

 

[ShaunCorbs]

Left hand side flow out the floor going upwards
Vent
Feed
Pump
Port valves for heating and hot water

If you want me to draw it out will knock something up tomorrow for you

 

[egizz983]

Left hand side flow out the floor going upwards
Vent
Feed
Pump
Port valves for heating and hot water

If you want me to draw it out will knock something up tomorrow for you

yes if you could that would be great

 

[John.g]

This is the general idea?.

 

[egizz983]

Yes and basicaly feed and expension pipe are the same . So if i understand this correctly best possition for he pump is on the flow right after t junction on downwards pipe that goes into rads and expansion pipe than would push water down then ?

 

[John.g]

My 50 year old system has the exact same combined cold feed and vent but the pump is installed just before the (oil fired) boiler return on the ground floor.

A bit surprising, if the rad returns were into the pump suction that it wasnt circulating through the rads at least.
I think yes, install the pump on the flow side and ensure the cylinder flow and rads flow pipes are downstream of the pump discharge, assuming that you want to have a fully pumped CH&HW system. I would also suggest installing a 1/2" gate valve on the cold feed to the Feed&expansion tank ballcock filling line as you should fill the system very slowly so as the air can vent up through the same pipe that the water is filling the system through.

 

[egizz983]

I have moved pump to different location it seems to be working noe all fine . But the problem doest really heat hot water very well qnd forst floor radoators as well . Both flow and return pipes are hot now all rads on second floor also hot but hot water cylinder and first floor rads cold or at least it takes way longer to heat them up .

 

[John.g]

I see the pump is on Auto setting, you might change that to a higher setting and post the make/model of the pump, most pumps, Grundfos etc just don't work on this Auto setting. Also the cylinder coil NRV should be removed IMO (if still installed) especially if a spring loaded type but try pump on different setting for a start.

 

[ShaunCorbs]

should be installed like this

 

[egizz983]

should be installed like this

port valves are essential ?

 

[egizz983]

I see the pump is on Auto setting, you might change that to a higher setting and post the make/model of the pump, most pumps, Grundfos etc just don't work on this Auto setting. Also the cylinder coil NRV should be removed IMO (if still installed) especially if a spring loaded type but try pump on different setting for a start.

if i take off NRV then it stops circulating . i would guess i need to redo feed and pump location . Put pump on flow before boiler and feed before pump like in example ShaynCorbs send

 

[ShaunCorbs]

port valves are essential ?

Yes else your overheating / no control over hot water and hot water isn’t pumped

 

[John.g]

I would think that it should work if you install in the horizontal pipe just above it and shift the vent to the left of it, that way the cold feed is to the suction side of the pump and the whole system should operate at a positive pressure. As installed IMO, should still work but not the best as system will be at negative pressure in places.
Ideally, should have mot.valve and balancing valve on cylinder coil as cylinder temp will run at the boiler temperature otherwise.
Shaun is showing the pump on the flow from the boiler, pump pumping away from the boiler (correctly), but the above mod should achieve the same IMO.

Have you changed the pump settings?.

 

[egizz983]

I would think that it should work if you install in the horizontal pipe just above it and shift the vent to the left of it, that way the cold feed is to the suction side of the pump and the whole system should operate at a positive pressure. As installed IMO, should still work but not the best as system will be at negative pressure in places.
Ideally, should have mot.valve and balancing valve on cylinder coil as cylinder temp will run at the boiler temperature otherwise.
Shaun is showing the pump on the flow from the boiler, pump pumping away from the boiler (correctly), but the above mod shouachieve the same IMO.

Have you changed the pump settings?.

Yes i tried to set to max but as soon as i take out NRV its stops circulating or atleast ot doest pump hot water from boiler though the system .

 

[John.g]

If the flow&return are as shown and directions correct and the cold feed is shown correctly then suggested mod should work IMO, there are hundreds of installations like this with the pump mounted high up at the cylinder some with a mid position valve close by. To get the system up and running you can always install the zone valve later but maybe install balancing valve with next mod. I don't have one (but do have a Mot.valve) and a 6M pump running at 3.5M can circulate 10 rads + the cylinder coil.

The most obvious question of all, are the flow and return pipes connected to the correct boiler points?.

I,m still a bit puzzled as to why the original installation (pump on return) didn't circulate through the rads as essentially it was the same as my system except that my pump is pumping into the boiler (return) at ground level and adjacent to the boiler, the cold feed is connected in exactly as yours is.
Two attic bedroom rads do run with a slight negative pressure but its never been a problem.

 

[ShaunCorbs]

If the flow&return are as shown and directions correct and the cold feed is shown correctly then suggested mod should work IMO, there are hundreds of installations like this with the pump mounted high up at the cylinder some with a mid position valve close by. To get the system up and running you can always install the zone valve later but maybe install balancing valve with next mod. I don't have one (but do have a Mot.valve) and a 6M pump running at 3.5M can circulate 10 rads + the cylinder coil.

The most obvious question of all, are the flow and return pipes connected to the correct boiler points?.

I,m still a bit puzzled as to why the original installation (pump on return) didn't circulate through the rads as essentially it was the same as my system except that my pump is pumping into the boiler (return) at ground level and adjacent to the boiler, the cold feed is connected in exactly as yours is.
Two attic bedroom rads do run with a slight negative pressure but its never been a problem.

The pump is on the rad circuit only john

 

[John.g]

Original pump location (on the return) achieved no rad circulation, why not.
Second pump location only achieves limited rad circulation but only if cyl coil NRV installed, also strange.
Where should it be installed if my suggestion above incorrect?.

 

[egizz983]

Original pump location (on the return) achieved no rad circulation, why not.
Second pump location only achieves limited rad circulation but only if cyl coil NRV installed, also strange.
Where should it be installed if my suggestion above incorrect?.

if i get this right i would need to move ether on return or flow but after or before boiler ,bypass valve . then have 3 way motorized valve that diverts either to cylinder or rads , and keep that NRV on return ? that would solve all problems i guess as it would heat up ether rads or cylinder first and then would switch to the other one . or ofc i 2x two way valves . but i though all this should work ether way without putting those 2 way valves as old houses dont have them

 

[John.g]

Where was the pump installed when you had the stove?

 

[egizz983]

Where was the pump installed when you had the stove?

on return . and behind cylinder there is two pipes going down straight to the stove , and another coil on the other side . So basically pipes on the right from rads was going behind boiler and down to the stove splitting into coil . So all i did basically is cut those pipes from stove and use the ones that on the left and new coil as well . its basically exactly how it was with the stove . Image on how it was and how it is now

 

[John.g]

OK , thanks, clear now,

Was there any particular reason for installing the new circ pump on the return but upstream of the cyl coil return, which required the NRV on the coil return (post #1) when you could have installed the pump downstream of the cylinder coil return and have a fully pumped system and have removed the NRV and installed a gate valve for balancing purposes, if required?. I can now see why removing the coil NRV stopped all circulation with that setup.

OK , "Second pump location only achieves limited rad circulation but only if cyl coil NRV installed," this is possibly because the cold feed is to the pump flow side but really shouldnt stop circulation but if you are OK to do it, I would relocate the pump & AAV as per post #26 and install a balancing gate valve in place of the coil NRV and then test the system again, you can just use the gate valve as a on/off valve for the cylinder coil, if the results are satisfactory then can look at installing other options re zoning.

Can you give me details of that new circ pump, name/model etc.

 

[John.g]

NO, STOP, looking at your set up you can't do it as I suggested as the pilpe on the right is NOT the flow from the boiler, its the flow pipe to the rads (hence my query), is that right.
this is the present set up, confirm if you agree.

 

[John.g]

Have a very good look at this please.

 

[John.g]

I am seeing TWO pumps now in post #8, time for the Jamesons.