New Rad cool at the lower part.

[nickjaxe]

Hi all, we had a new worcester 30si boiler fitted about 9 months ago to replace our 30 year old Baxi back boiler,

The installer said our existing rads looked ok which pleased me as I didn't fancy all the floor having to come up,

Its work fine very happy except that he had to put some leak seal in the sys to cure a very slight leak that was not easy to find....I had to top up the sys every 2 weeks from 1 bar back to 1.5 bar....anyway that cured it,

A few weeks ago the rad in the up stairs main bed rood was quite cool on the lower 1/4 and the room was not that warm....I suspected that the rad was sludged up so I ask our fitted to take a look....he said yes the rads goosed...so I asked him to fit a new rad...its slightly smaller at about 1200 x 900 aprox,

The old rad which was again at least 30 years old had none of the fins on the back that modern rads have....which the new one does,

But I have noticed that the new rad seems the same...cooler on the lower 1/4 in fact very cool near the bottom and the very top does not seem as hot as the rest of the old rads in the house which are very hot to the touch....must admit though the room does seem warm,

Does this cool at the bottom seem ok or should I ask the guy to come back and take a look,

The boiler is upstairs now as is the suspect rad,

He did fit a thermoelastic valve on the new one but I screwed the top off that to discount that that was not at fault....with the top removed there is no difference...still cool lower down....also the outlet pipe is quite cool....the inlet very hot,

What do you think guys???

Nick in Cheshire.

 

[PlumbBobBob]

probably needs balancing is the outlet fully open?

 

[nickjaxe]

Yes it is fully open well its fully out....is the water forced to follow a route around the rad or is the whole lot free flow

Nick.

 

[GQuigley67]

doesn't seem like the water is circulating very good at this rad by the time it gets to the outlet it has cooled down, the system will need balanced...

don't know why he said to you the radiator was "goosed" though, at best it would of needed flushed out

 

[GrahamM]

doesn't seem like the water is circulating very good at this rad by the time it gets to the outlet it has cooled down, the system will need balanced...

don't know why he said to you the radiator was "goosed" though, at best it would of needed flushed out

30 years on an open system can result in layer upon layer of calcification and crud that no amount of flushing can shift. Sometimes replacement is only option.

Did you try shutting of all other radiators and leave the problem one fully open. As others have said, sound like may be a balancing issue.

 

[nickjaxe]

Update....got the guy that fitted the new rad to call in today to take a look at the new rad that is cool at the bottom....I was at work but he says the prob is that I didn't have the boiler heat control set to full....I think I had it on 4,


Anyway sure enough the new rad is pipping hot in fact they all are....a bit to hot to keep your hand on for more than a few secs....what do you think guys,

I will post a new question re the best way to set our boiler.

Nick.

 

[ziggy]

For an upstairs rad you would normally only have the return valve partially open (sometimes as small as half a turn) in order to ensure that the water was held up in the radiator and pushed on via the flow side to the next radiator in the system. Turning up the boiler will just increase the heat of what little water is being held in that radiator and for all of the other radiators also ... so it may give you the effect needed but isn't a cost effective way of solving the problem.

You could assume that as all the other radiators haven't been changed then the system is still balanced overall and you just need to balance that one radiator by reducing the flow on the return side and turn the boiler temp back down.

If that doesn't work ... nothing lost ... just open up the return valve again and turn the boiler temp back up!

 

[nickjaxe]

That make sence Ziggy....I will give that a go.

Nick.