Central Heating motor in loft - ok on 3rd speed?

[Tempest]

Central heating has been performing very badly recently, boiler and thermostat has been running fine but the water does not appear to be circulating into the radiators very well.

The bedrooms rads especially are only getting luke warm (they are on the ends of a long run of pipework)

Tonight I've made a vast improvment by going up into the loft and bleeding all the air vents I could find (helped a bit) and I also adjusted the speed on the central heating pump motor from 2 speed (which it was on) up to number 3 speed.

(it has 1, 2 and 3 speeds)

This is making the water circulate a little faster (with perhaps a little more push to the water) and it's now finally making its way to the furthest away radiators in the bedrooms.

Can anyone please confirm for me that it's ok to turn the speed of the motor up from it's number 2 speed setting, up to number 3 to move the water a little faster.

It won't do any damage to anything will it, or affect the motor?

Thanks

Oh yes, it's a pump that looks like this:
http://www.tlc-direct.co.uk/Main_Index/Heating_Index/Central_Heating_Other_2/index.html

As it's just sitting on some chipboard on the loft floor, the motor pitch has changed a little and you can hear a different tone downstairs. It's not noisy, just rumbling the wood it's sitting on a bit.

But as I said, is it fine to turn the speed up 1 notch from 2 to 3 ?

 

[Agile]

That pump is fine but it would be more professional to say its a 15-50.

You should not need to put it on 3 but it will not do any harm apart from being more noisy.

Either the system has become sludged up or needs balancing.

Turn DOWN the hottest rads and see what effect that has on the furthest ones.

It should operate fine on setting 2 !

Tony

 

[Tempest]

That pump is fine but it would be more professional to say its a 15-50.

You should not need to put it on 3 but it will not do any harm apart from being more noisy.

Either the system has become sludged up or needs balancing.

Turn DOWN the hottest rads and see what effect that has on the furthest ones.

It should operate fine on setting 2 !

Tony

Thanks for that.

the truth is that the whole system is probably a bit of a hash.

The house used to have a gravity fed coal boiler.

Then we had it changed to a new pumped coal boiler and then finally a gas boiler

At no time was the system replumbed and re-routed so it's a bit of a rats nest of 3 different mods up in the loft.

The pipes are old and a bit furred up I've no doubt.

I'm thinking perhaps the extra pressure is at last getting the water to the furthest rads.

to make matters worse, in the loft there is one pipe thats about 10 feet long, this them splits into two (with a t piece) then these two pipes them travel about 13 feet across the loft, then down into the 2 bedrooms and into the rads, so no only are they the furthest away, they are also sharing 1 feed pipe in the loft also.

I just wanted to know the pump will be ok running at speed 3 during these cold months (I can turn it back down when it warms up)

It's not VERY noisy at all, but it's more noisy on 3 than on 2 with a little extra vibration.

Going to try and put some foam to deaden the sound as the chipboard is vibrating the loft beams which can be heard downstairs.

 

[Agile]

Its almost midnight when I turn into a pump!

Its amazing what some people put up with!

Tony

 

[HarrogateGas]

Id be carefull with the pump on speed three in the loft. If the system is open vented there is a quite a large chance that on speed three the intial inertia of when the pump kicks in will pull air in. You also (depending how the system is configured) increase the chance of it 'pumping over'. Both scenarios need checking to avoid costly powerflushes in the future.

 

[Nige F]

Hi, "rats nest"...."one pipe feeding rads" sounds interesting....can you post some pics?..............might be a one pipe circuit from the coal days, in which case you`ll have a job balancing the rads..........are there any motorised valves controlling hot water/heating?.......How is the pipework from the feed tank in relation to the pump.

 

[Tempest]

Sorry for the dealy in getting back:

I would just like to thank everyone for all the tips and advice re my original posting.

Since doing the bleeding of some air (helped a bit) and the increase the pump speed to 3, our cold radiators in the bedrooms have become lovely and hot.
In fact they are the hottest they have been in years (and how they should be)

I have looked more closly at the layout in the loft, and to summerise:

You have the pump, then straight after the pump you have a pipe which goes straight on and a T piece in it (so basically it splits into 2) directy after the split on both routes are electronic valves.

One of which is the hot water, the other the heating.

I'll ignore the hot water as that's fine.

So the water goes thru the open valve (heating) and then climbs up about 12" to 18" up then into a T piece which connects into a LONG pipe which stretches the entire width of the bungalow.

this LONG pipe goes downhill towards the ends. One end splits into two, into other long runs to feed two radiators via individual feeds

The other end goes to one rad, and about half way along it splits off to yet another rad.

That all sounds a bit complex.

so to put it simply

The water is pumped UP into a long pipe, and the pipe has various feeds off, which end up dropping down individually feeding rads downstairs.

I'm guessing they all may come together in some sort of common return (not sussed the returns out yet as they are unde the floor.

So, we don't have a loop as such, we have one feed, splitting (like spiders legs) down into individual rads. and then returning.

Of course, I guess the issue here is the shorter loops are going to get hotter than the longer loops, and also more pressure is needed to get the water all along the longer loops.

Does this sound a weird system, or quite common?