Radiators Plumbed in to Hotwater

[Tim123]

Agree, and the hot water going cold in the cylinder has nothing to do with the rads being connected to the HW circuit (unless theres a permanent overun on the pump?)

The Vailant's display shows that the pump is running most of the time. Not sure if this is for the HW circuit or the CH circuit or both.

 

[markproperjob]

COPPER RADS??? OH HOW I WISH THOU EXISTED!!
I'd have the red carpet rolled out every time i visited our local metals merchant!!
ive only seen one rad plumbed into the dhw heating circuit, on a job im due to re vamp in march. told customer straight off 'thats got to go!!'
but to be fair, the total abomination of 1/2'' pipe snaking its way around the bathroom and into the airing cupboard gave the game away slightly!
one thing i came across recently when replacing a cylinder in a cornish farmhouse was the cylinder was connected to a solid fuel AGA with 3/4''piping, and looked just like a standard indirect cylinder without any insulation.
only after a (very)long drain down, and re connection of a new indirect cylinder, did i discover that there was no feed and expansion tank, but the cylinder had been piped to allow water to gravity feed directly from the side of the cylinder, into the aga, and then return heated into the cylinder!
water was always rusty at rhe taps!
there was no coil inside the old cylinder.
i had to install a new f/e tank, but did so at a fair price due to fact i hadnt spotted this setup!

has anyone else ever come accross this kind of cylinder? looks exactly like a standard indirect, but has no coil, but still has side outlet/inlet to heating circuit??

 

[Bartdude]

one thing i came across recently when replacing a cylinder in a cornish farmhouse was the cylinder was connected to a solid fuel AGA with 3/4''piping, and looked just like a standard indirect cylinder without any insulation.
only after a (very)long drain down, and re connection of a new indirect cylinder, did i discover that there was no feed and expansion tank, but the cylinder had been piped to allow water to gravity feed directly from the side of the cylinder, into the aga, and then return heated into the cylinder!
water was always rusty at rhe taps!
there was no coil inside the old cylinder.
i had to install a new f/e tank, but did so at a fair price due to fact i hadnt spotted this setup!

has anyone else ever come accross this kind of cylinder? looks exactly like a standard indirect, but has no coil, but still has side outlet/inlet to heating circuit??

I think you'll find that was a Direct cylinder,it used to be very common for an Aga to be used with a direct cylinder,the cast iron boiler in the cooker has a vitreous lining that stops it contaminating the hot water,eventually the lining breaks,hence rusty water at the taps.The boiler will usually start leaking subsequently,although it can go unnoticed for a long time as the water evaporates with the heat of the Aga.
Aga still make the cast iron boiler but I fit a third party replacement which is made from stainless steel.Of course most systems are indirect now but there are still a few direct cylinders out there,it's worth making the point that it's not such a problem in this part of the country(South West)as the water is so soft there so limescale is not such an issue.

I'd guess the lining in the boiler was shot on your job,but now you've changed to indirect it won't be a problem until the boiler starts leaking.The 3/4"pipes should have been 1'' by the way as they work on gravity circulation.

When range cookers supply hot water it's common to have a heat leak radiator and if it's a direct cylinder then the rad mustn't be steel,I've seen a couple of copper ones,but brass is more common.Stainless steel is the most cost effective though!!

 

[raymondo68]

I don't think that a summer circuit (bathroom rad on HW coil) complies with PART L??

My solution is to fit a towel radiator with an electric immersion for the summer.

Ask original plumber to come back with a fair price for the alterations.

good luck

raymondo

 

[Tim123]

I don't think that a summer circuit (bathroom rad on HW coil) complies with PART L??

My solution is to fit a towel radiator with an electric immersion for the summer.

Ask original plumber to come back with a fair price for the alterations.

good luck

raymondo

Problem is plumber has moved 2 hours drive away.

What is part L - is that a building regulation?

 

[raymondo68]

Part L is a building regulation (Conservation of Heat and Power). All heating circuits must be controlled by a timer and a thermostat. The bathroom radiator is heating a space that is not controlled by a thermostat.

Depends what the original plumber is like....... a bit of good old fashioned negotiation me thinks!

 

[Gray0689]

If your radiators in the bathroom are on the hot water circuit to/from the cylinder that is correct and is still current practice (this means you canh dry towels on them in the summer when the heating is switched off). For a ch/hw system I usually do plumb the towel rail into the hot water not the central heating.

The way to solve your problem is to restrict the flow to the radiators in question by cranking down the lockshields.

The other poster is getting mixed up with a DIRECT cylinder, a very old fashioned idea in which the towel rails should be made from brass.

This is not current this is old fashioned towel rails can and should be put on there own circuit

 

[Deleted member 2053]

Bearing in mind that heat rises and the coil for heating the hot water is well down the cylinder, then the only way that the radiators are going to make the cylinder water go cold is for them to be fed with tap water in which case, as already stated above, you either have copper/brass rads or you would be replacing them (and your ceilings) on an annual basis, so you may be mis-diagnosing the problem here. Most of my customers regard having a bathroom rad that keeps towels warm all year round as a feature rather than a burden, though I would normally bring the fact to their attention in case they wanted it changed. A rad can always be made to turn off in summer through the use of a thermstatic rad valve. Get the guy back and talk nicely to him, though from what you say I would expect the work to be chargeable.

 

[WHPES]

Radiators on the DHW circuit are fine regarding Prt L as long as you have a TRV fitted. I asked my old tutor about this and that is what he said, and he is an expert in the industry. I have fitted several up this way and the building inspector has never once commented.

You can't get copper radiators but you can get all brass or stainless ones for use with direct cylinder systems. (and yes.. they are quite pricey)

 

[Gray0689]

Radiators on the DHW circuit are fine regarding Prt L as long as you have a TRV fitted. I asked my old tutor about this and that is what he said, and he is an expert in the industry. I have fitted several up this way and the building inspector has never once commented.

You can't get copper radiators but you can get all brass or stainless ones for use with direct cylinder systems. (and yes.. they are quite pricey)

Old fashioned

 

[mboshier]

I fit all my towel rails on the primaries then they heat up when you call for hot water so when you get out the shower in the summer the towel rail can be warm!

 

[ecowarm]

it was not uncommon to have towel rails off the secondary circulation (pumped hot water circuits) on larger properties