Question for heating engineers/plumbers re two hot water cylinders

SaxmanUK

I have two hot water cylinders (why? its a barn conversion)
One is new and runs off an oil boiler and feeds three bathrooms
One is older and feeds another bathroom and the kitchen hot water. This is heated by an AGA (oil).
With the cost of oil gone up, plus I want to turn off the aga in the summer months, I want to add another zone valve from my oil boiler and run the new pipes to the existing hot water cylinder (run by the aga convection) I will then disconnect the pipes from the aga.

I am thinking to fix a thermo to the cylinder that will open the valve when required and pump the hot water from the boiler.

Am I talking sense or should I only use 1 hot water cylinder to feed the whole house

PLease comment

Thanks in advance

Sean

plumb1_2

SaxmanUK wrote: »

I have two hot water cylinders (why? its a barn conversion)
One is new and runs off an oil boiler and feeds three bathrooms
One is older and feeds another bathroom and the kitchen hot water. This is heated by an AGA (oil).
With the cost of oil gone up, plus I want to turn off the aga in the summer months, I want to add another zone valve from my oil boiler and run the new pipes to the existing hot water cylinder (run by the aga convection) I will then disconnect the pipes from the aga.

I am thinking to fix a thermo to the cylinder that will open the valve when required and pump the hot water from the boiler.

Am I talking sense or should I only use 1 hot water cylinder to feed the whole house

PLease comment

Thanks in advance

Sean

Yes you can do this, link the zone valve to a cylinder stat, also put in a auto airvent, and i would put in a bypass valve set low.
If your new cylinder is large enough, you could think about putting in a secondary circulation pipe from this cylinder to the hot water pipes, and only use 1 cylinder.

SaxmanUK

plumb1 wrote: »

Yes you can do this, link the zone valve to a cylinder stat, also put in a auto airvent, and i would put in a bypass valve set low.
If your new cylinder is large enough, you could think about putting in a secondary circulation pipe from this cylinder to the hot water pipes, and only use 1 cylinder.

Many Thanks
However I thought a auto air vent was for central heating and not domestic hot water?

plumb1_2

SaxmanUK wrote: »

Many Thanks
However I thought a auto air vent was for central heating and not domestic hot water?

Basicly you are heating the coil in the cylinder, and you need to vent it, just like a rad needs a vent.

SaxmanUK

plumb1 wrote: »

Basicly you are heating the coil in the cylinder, and you need to vent it, just like a rad needs a vent.

Of course I do, I should have known that!

Can I ask another question please?

My boiler has two feeds and two returns to it
Would you use 2 pumps and two feeds?

i.e. left side would pump and return both cylinders
right side another pump, would feed the two CH zones?
I understand you can get circulation problems using two pumps if both the water and CH are on at the same time?

Again Thanks, I just love forums!

Sean