CH pump from thermal store and blender position.

[jasontaz]

I'd remove that valve.
It's serving no purpose other than possibly diverting flow back to the store thus preserving the temperature to a degree.

The HW coil should be above that level and be unaffected ideally.

Those pretty diagrams are for illustrative purposes only. They show a three port valve on the flow from the boiler and the connections to the store coil. Again not needed.

Thanks for that. If the water in the Thermal Stores was top to bottom 80 deg C and the ch kicked in, surely you would need a blender to stop the water from being too hot for rads?

That's me again. It actually showed additional rads in the bottom right that were not connected to the thermal at all, i.e. came off at that 3 port, round the rads and back to the cold on the boiler. Sorry, I thought I would make it clearer by removing the bits I didn't have (including under floor heating).

So no blender then.
Regards,
Jason

 

[Onetap]

I'd remove that valve.

I'd keep it but re-pipe it.

I think it's intended to act as a mixing valve to keep a constant temperature to the rads when the store is very hot. It's a blending/mixing valve and should have two inlets and one mixed outlet with the pump suction connected to that. I don't think it will work in the existing arrangement (assuming it's still in working condition).

 

[matt1e]

I'd remove that valve.
It's serving no purpose other than possibly diverting flow back to the store thus preserving the temperature to a degree.

The HW coil should be above that level and be unaffected ideally.

Those pretty diagrams are for illustrative purposes only. They show a three port valve on the flow from the boiler and the connections to the store coil. Again not needed.

Thanks for that. If the water in the Thermal Stores was top to bottom 80 deg C and the ch kicked in, surely you would need a blender to stop the water from being too hot for rads?

No as your store and hence your rads will only ever get as hot as the heat input from the heat source
it is the same situation as if the rads were being fed direct from the boiler
There are valid reasons to use a blending valve where it is but that would be as a secondary safety device for limiting/safety reasons
No valid reason for the pump position if it is in fact part of the heating system
Do you have underfloor heating or a wood burner?

Matt

 

[bolshy]

Well, the data sheet I read said that your blending valve is suitable for heating. Your pump should be be on the system side of the valve, on the flow leg, not between the coil and the valve. This will alleviate any pressure difference problems.
Depends on what temperature you want to keep your rads at, relative to the store. If you need them lower, then you need the valve.
You need to have the pump in the right place on the system. Colder return leg enters the bottom of the valve. A check valve might be held shut if you fit one with your pump in it's current position.

 

[Agile]

Even that Gledhill diagram is wrong!

It shows a TRV on the heat dump radiator above the multifuel stove. No TRV should be fitted ( unless it was a special reverse action TRV ).

Tony

 

[jasontaz]

Tony:

Even that Gledhill diagram is wrong!
It shows a TRV on the heat dump radiator above the multifuel stove. No TRV should be fitted ( unless it was a special reverse action TRV ).

Yes, I can see that would be a bad idea.

No as your store and hence your rads will only ever get as hot as the heat input from the heat source
<snip>There are valid reasons to use a blending valve where it is but that would be as a secondary safety device for limiting/safety reasons
No valid reason for the pump position if it is in fact part of the heating system
Do you have underfloor heating or a wood burner?
Matt

Woodburner and I think the thermal store vents @ 80 - 90 (actually the solar vents when the bottom gets to 80 and I think the top is 85 or 90), so I can see the need for something.

Well, the data sheet I read said that your blending valve is suitable for heating. Your pump should be be on the system side of the valve, on the flow leg, not between the coil and the valve. This will alleviate any pressure difference problems.
You need to have the pump in the right place on the system. Colder return leg enters the bottom of the valve. A check valve might be held shut if you fit one with your pump in it's current position.

Thanks, do you have a link to the data sheet and / or docs on position of the pump. I need to go back to the installer and get it remedied.

You have all been a great help. I'll step over to the software section to see if I can return the favour somehow.

I have other questions, but will start a new thread:
- air distribution system (living room too hot with stove, kitchen too cold, thermal store on wood only not able to heat kitchen enough).
- Is my thermal store big enough?

My take away at the moment is:
- Pump required (otherwise no delivery to the rads)
- valve required if thermal store much hotter than we want the rads
- Pump position - consensus is on the other system side (which I assume is rad side), but 2 views, one of the flow and the other on the return.

 

[Onetap]

My take away at the moment is:
- Pump required (otherwise no delivery to the rads)
- valve required if thermal store much hotter than we want the rads
- Pump position - consensus is on the other system side (which I assume is rad side), but 2 views, one of the flow and the other on the return.

The existing pump and mixer valve should do all that, once they're installed correctly. You don't need another pump. The blended port on the valve is always open, so the pump inlet connects to that and the pump outlet goes to the CH flow.

Even that Gledhill diagram is wrong!

It shows a TRV on the heat dump radiator above the multifuel stove. No TRV should be fitted ( unless it was a special reverse action TRV ).

Well spotted. There's an odd motorized valve on it as well. CAD is great, it allows small errors to be easily copied and pasted all over multiple drawings.

 

[bolshy]

The data sheet I read was the one you posted. I just read it properly.

Pipe up or move your pump to the other side (left) of the blending valve on your diagram. Inlet connected to blending valve, outlet to rads. Should work then, job done.

 

[Norcon]

The OP's data sheet wouldn't download unto my pc so I went to the esbe website direct and down loaded the one below unto my lap top which covers their thermostatic range of valves.

Page 150 shows the 310 series...
http://infoweb.esbe.se/files/55666/Thermostatic Control Units_GB_99501362_A_LR.pdf

It doesn't show a "secondary alternative" application for the valve. Thats not to say it won't work outside its design parameters.
Thats my story and I'm sticking to it.

I'd still remove the valve and maintain the store temp to a maximum of 70c.
Heat dump stat for the solid fuel will acheive that easily.

Your in a "slightly to moderately hard" water area, so the higher temps will start cooking limescale unto the dhw coil and from there on its a hot water dribble coming out of the taps.

Whats the hot water delivery like as a matter of interest?

 

[jasontaz]

The data sheet I read was the one you posted. I just read it properly.
.

Ta, yes, I start reading and when I don't understand 10 things, my brain shuts off.

Page 150 shows the 310 series...
http://infoweb.esbe.se/files/55666/Thermostatic Control Units_GB_99501362_A_LR.pdf

It doesn't show a "secondary alternative" application for the valve. Thats not to say it won't work outside its design parameters.
Thats my story and I'm sticking to it.

It doesn't, but it also doesn't explicitly have a CH row, just an underfloor.

On the same page What does: "This series of valves is not suitable for domestic hot water installations equipped with HWC" mean?

I'd still remove the valve and maintain the store temp to a maximum of 70c.
Heat dump stat for the solid fuel will acheive that easily.

Your in a "slightly to moderately hard" water area, so the higher temps will start cooking limescale unto the dhw coil and from there on its a hot water dribble coming out of the taps.

Whats the hot water delivery like as a matter of interest?

Temp to ThermalStore: The trouble is that it is a Gledhill SOL 210 and we have a fairly high flow rate. If the fire has been on and not the gas and the heating has been on, it drags the TS temp down in the bottom 1/2 of the tank as you would expect. This leave 1/2 the tank to heat the water for our highest usage app = shower. So say, 100L of water to supply a shower @ 12+L a minute, very quickly becomes a very cool shower unless either the temp diff is higher or you slow the water down. You very quickly get to a point where the more you open the tap the cooler the water. It was supposed to be the next one up (270?), but it wouldn't fit in the airing cupboard and the installer said this one would be fine, but I think it might be undersized for our house etc.

Thanks for thinking of the limescale, you are the first to do that and I hadn't considered it at all.

Hot water delivery: flow - very high - thinking of reducing the flow as it comes into the house for the above reason. Temp: fine if CH not on. One shower if CH has consumed the bottom part of the tank.

Thanks all again. Any additional thoughts welcome.

 

[Onetap]

On the same page What does: "This series of valves is not suitable for domestic hot water installations equipped with HWC" mean?

Hot water circulation (top of page 126)