Radiators Plumbed in to Hotwater

[Tim123]

Last August we had some major plumbing work done on our house and I'm not completely satisfied with the results. I'm just trying to figure out if this was the fault of the plumber or not.

We upgraded our 30+ year old boiler to a Vailent system boiler, added an extra radiator in the toilet, but left all existing radiators and the hotwater cylinder as they were.

At first everything seemed fine, but soon I realised that the 2 radiators in the bathroom and toilet were not on the central heating circuit, but were on the hotwater circuit. This was the way it had been installed 30+ years ago.

Its a problem because the stored hotwater goes cold in just a few hours because the radiators let the heat escape. Also if the hotwater is not on, then the bathroom is cold.

Should this problem have been picked up by the plumber?

 

[CES]

Just to clarify, the radiators are on the HW coil circuit? If this was the way it was installed previously did you not notice the problem before the work was done?
I would be inclined to talk with the plumber and explain your concerns but I dont think he can be liable for an existing condition.

 

[Tim123]

Just to clarify, the radiators are on the HW coil circuit? If this was the way it was installed previously did you not notice the problem before the work was done?
I would be inclined to talk with the plumber and explain your concerns but I dont think he can be liable for an existing condition.

Yes that's right.

The last boilers controls were so basic that you had to run the hotwater and heating together on the same timer - so it was not apparent.

Another plumber has said that putting the bathroom radiator on the hotwater circuit was normal 30+ years ago. If that's right then shouldn't checking for this problem be a standard part of upgrading a very old boiler?

 

[CES]

It all depends on who the plumber is and his historical knowledge of plumbing. To put it right will involve re-piping the rad into the heating circuit which is something I wouldn't have expected as part of a boiler upgrade to be fair.

 

[kimbo]

I think the plumber should have checked the whole system and advised the customer accordingly, however the extra work to be done would have to be paid for by the customer as it wasnt charged for at the time. Bread and butter stuff really.

 

[plumber0808]

you say its a problem but its been like that for 30 years? engineer only changed the boiler so nothing on the system will be any different.
phone the plumber back asking for them to be changed. im sure he he found out it was like this when testing which i have done in the past.
you will just have to pay to sort it out if you want it any different

 

[GrahamM]

It all depends on who the plumber is and his historical knowledge of plumbing. To put it right will involve re-piping the rad into the heating circuit which is something I wouldn't have expected as part of a boiler upgrade to be fair.

Agree with CES here. Although was a bit of an oversite, the plumber was charged with installing boiler and extra rad. Correct? He should have picked up on it and advised accordingly though. Don't know how he missed it if he set up and commissioned the install fully.
If you are happy with the boiler work he done, get him back and ask him for reasonable price to upgrade the rest of the installation, as it was his oversite and he should hold some of the responsibility.

 

[stevetheplumber]

in a way your lucky if you had changed to a combi niether rad wold work

 

[justlead1]

Hi. If the rads have been on the domestic hot water distribution pipe? They would have corroded and leaked many years ago unless they were manufactured with copper.

 

[smillsey]

mmmmmmmmmmm copper rads £££££

 

[WHPES]

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.

 

[Tim123]

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.

Thanks for the useful info - I will try to crank down the lock shield. Cheers!

 

[gaspastemania]

Think its a bit harsh to say the plumber should have picked this up to be honest , he has not charged for it either . . His comission tho was obviously a bit wayward if any comission lol!!!

 

[PlumbingSucks]

if you plumb towel rails off hw circuit then when hot water is satisfied towels would go off even if heating is still on?

 

[Blackcatgas]

if you plumb towel rails off hw circuit then when hot water is satisfied towels would go off even if heating is still on?

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?)

 

[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