Hot water too hot

[jack]

The Aga on the ground floor supplies hot water to a hot water cyl on the ifrst floor. The HW cyl was 20 galls against a recommended 40 galls so the bathroom rad was added and connected to the AGA circuit to absorb some heat, this worked well.

4 years ago I installed a separate boiler and rads for central heating and I disconnected the bathroom rad from the AGA circuit and hooked it into the boiler circuit and it worked fine.

The EH and coil failed in January, so I replaced the cyl with a 35 gallon tank.

This new HW Cyl has good insulation unlike the previous one which had the four red panels strapped to it which came lose and fell to the ground.

But the water from this new HW cyl gets too hot so I disconnected the bathroom rad from the boiler circuit and reconnected it to the AGA circuit to as before.

But the rad does not heat up so I'm trying to figure why.

The feed for the rad is tapped in the loft, about 3 feet from the expansion tank, to the expansion pipe for the AGA which in turn comes off the flow to the HW cyl.

But the expansion pipe is only just warm in the airing cupboard above the HW cyl, which makes me think that the insulation on the tank is very good and no excess hot water is produced to heat the rad.

The return for the rad is tapped at the AGA return..

The rad bleeds water with obvious pressure so apparent blockage.

If I remove some of the insulation will this cool the HW down?

 

[oldplumber]

if the hw cyl is getting to hot you need to look at your cyl stat, not start disconnecting rads etc, from some of your ideas i believe you best bet would be to stop messing around with things you dont understand and call in an expert or sooner or later your going to cause yourself a major problem. diy can only go so far, remember you may want to sell your house one day, a surveyor may find problems with what youve been doing

 

[Puddle]

The Aga on the ground floor supplies hot water to a hot water cyl on the ifrst floor. The HW cyl was 20 galls against a recommended 40 galls so the bathroom rad was added and connected to the AGA circuit to absorb some heat, this worked well.

4 years ago I installed a separate boiler and rads for central heating and I disconnected the bathroom rad from the AGA circuit and hooked it into the boiler circuit and it worked fine.

The EH and coil failed in January, so I replaced the cyl with a 35 gallon tank.

This new HW Cyl has good insulation unlike the previous one which had the four red panels strapped to it which came lose and fell to the ground.

But the water from this new HW cyl gets too hot so I disconnected the bathroom rad from the boiler circuit and reconnected it to the AGA circuit to as before.

But the rad does not heat up so I'm trying to figure why.

The feed for the rad is tapped in the loft, about 3 feet from the expansion tank, to the expansion pipe for the AGA which in turn comes off the flow to the HW cyl.

But the expansion pipe is only just warm in the airing cupboard above the HW cyl, which makes me think that the insulation on the tank is very good and no excess hot water is produced to heat the rad.

The return for the rad is tapped at the AGA return..

The rad bleeds water with obvious pressure so apparent blockage.

If I remove some of the insulation will this cool the HW down?

removing some of the insulation will help also ventilate cupboard however ,not great idea, better you should add /refit the heat sink rad as per original design although you have increased cylinder size,sure not just air locked,also double check vent is not blocked/badly partly blocked,rad should work if water getting hot/to hot regardless of insulation

imho

 

[jack]

if the hw cyl is getting to hot you need to look at your cyl stat, not start disconnecting rads etc, from some of your ideas i believe you best bet would be to stop messing around with things you dont understand and call in an expert or sooner or later your going to cause yourself a major problem. diy can only go so far, remember you may want to sell your house one day, a surveyor may find problems with what youve been doing

There is no HW cyl stat.

removing some of the insulation will help also ventilate cupboard however ,not great idea, better you should add /refit the heat sink rad as per original design although you have increased cylinder size,sure not just air locked,also double check vent is not blocked/badly partly blocked,rad should work if water getting hot/to hot regardless of insulation

imho

Thanks I'll check for any blockages or air locks.

 

[WHPES]

Sounds like an airlock.

You could solve the heat problem by fitting an extra loop onto the circuit with radiators and a pump, controlled by a pipe stat. When the primary pipe return gets over 60 degrees, the pipestat sets the pump going and dumps the heat into the circuit with the radiators.