Cylinder thermostats

[garymusson]

I have a hot water cylinder that is gas fed with the immersion disconnected, but it currently has no thermostatic control and continues to boil like a kettle, giving near-boiling water from the taps! Is it possible to attach a thermostatic valve to the inlet pipe connected to the cylinder thermostat (not currently present) by a copper wire so that it regulates the water temperature in the way similar to a radiator without the need to link back to the control pad and without the need to install a motorised valve?

Thanks

 

[gas4you]

It is called a tap stat and made by Drayton. I assume they are still available

 

[LUNAT]

HI
yes it is possible. you can buy it from parts centre
it is fitted to the flow pipe near the cylinder and the sensor is attached to the cylinder, not on the expansion pipe.

 

[garymusson]

Thanks Lunat and Dave - I thought you could get such a thing.

Now is this something that a capable DIYer can take on, or would it be advisable to get a corgi registered plumber to install it? I understand problems can occur when you drain down and refill the hot tank, but if it is reasonably easy, I may take it on myself. Would you also advise putting an isolating valve either side of the tap-stat?

Again, many thanks for your posts

Gary

 

[JohnD]

Or a Cyltrol

http://www.invensyscontrolseurope.c...rvices/Drayton/Nonelectroniccylindercontrols/

 

[garymusson]

Thanks John - it says in the blurb about the Cyltrol that it is not suitable for a primatic cylinder - sorry for being stupid, but what is that?

How does this one work if it is not linked by the capillary to a thermostat on the tank?

Is it as good/better than the Drayton?

Regards

Gary

 

[JohnD]

it has a thermostat inside which reacts to the temperature of the water in the return pipe where it is fitted. when the cylinder is fully hot, the return pipe will also be hot (as it is no longer passing through a cold cylinder) so it shuts off gravity circulation until it cools down again.

it is expensive, something like £80 I think

I don't know if its better or worse than the other one - was in fashion 30 years ago when gravity HW circ was common.

I hope you haven't got a Primatic cylinder - they are very rare now - they do not have a feed & expansion tank in the loft but have an air bubble inside. If you have a Primatic it will be so old it does not have a rigid foam coating in blue or green, and will probably have an identifying label or painted name on it. Post a pic of the cylinder and its pipes if you are unsure.

I am watching this thread because my mum's old system has a Cyltrol, and it is set very hot and I can't turn the spindle

The tapstat looks like it is based on rad valve technology - have you seen a price for it?

 

[garymusson]

Thanks John

I don't think we have a primatic cylinder, but now have the problem of not enough space to fit the Drayton Tapstat, and may have to shift the whole tank over by a couple of inches! Which could end up being more hassle than it's worth.

The Drayton's are about the same £75-80
http://www.uk-plumbing.com/acl-drayton-invensys-tapstat-28mm-2-way-gravity-p-1382.html

Hope you manage to free up your Cyltrol.

Gary