Townhouse radiators at varying heat levels??

[karenmac]

Hi
We live in a townhouse and have had heating problems for a few years but managed to get by.

We've just turned on the heating and only two radiators get hot - bedroom on top floor and bathroom on top floor
Two are look warm - bedrooms on top floor

There are 13 radiators in total.

Have tried (found in previous posts) turning on heating without hot water on and turning off hot radiators. The 2 rads that were look warm on top floor got hotter one significantly more than the other. As they got warmer the middle floor got warmer but not all rads and ground floor rads were still cold. This was after 5 hours.

Not all radiators have thermostatic valves the ones that do are Westherms and I'm not sure how to get them off to look at pins (previous posts)

Since house has been built 22ish years ago three radiators have been added. Do we need a new pump do deal with extra rads? (we have already replaced pump a few years ago)

Boiler is a Potterton netaheat electron 10/16 which we suspect came with the house. Does that need replacing?

My other half has drained system last year and this year and each time was filled with black liquid. Do we need a powerflush?

All the above solutions all have different cost implications and even then we might be barking up the wrong tree.

Thanks Karenmac

 

[timtheenchanter]

was there a reason you drained the system??

try bleeding the radiators (if you havn`t already)

 

[kevplumb]

might be an idea to

1 take a pic of the valves

2 try some fernox in the system

 

[bengasman]

Start off with buying a few bottles of either kamco hyperflush (can stay in the system for up to 4 weeks) or fernox f3 (2 weeks).
You will have to wait until you have the heating on most days, otherwise it does not do a lot. This might be saving you a powerflush at somewhere around £400.

Don't worry about the pump, it will do the job unless it is worn out.

Boiler seems a bit on the small side; measure the total length of radiator panels and see if you go over 16 metres.

FAQ gives you further details on cleaning systems.

 

[karenmac]

Hi

thanks for the replies.

Last year we drained the system as the lower rads weren't heating, whereas now its most that aren't. When we did it last year we put in possibly fernox left it for a few weeks and then cleared and replaced with a preserver??

This year we were replacing the rad in the downstairs loo and since downstairs still wasn't consistently warm, thought we would drain again.

It seemed last winter that the top two floors would eventually get to the right temperature and then the rads downstairs would heat. Also, it seemed to take ages to get to the right temperature, generally heating came on around 3pm to try and get it warm enough by evening.

Other half has checked valves and they are ok.

His possible theory is that the pump we have at the moment senses when the valves "think" they are at the right temperature and it shuts down. He is looking at buying a pump that has a mode that keeps at full power and he hopes that by using that mode it would clear any blockages.............

I have taken the length of the radiators and they total 1545 cms without our ensuite one which has three tubes of 130cms with 20cm circumference.

If we use kamco or fernox you mention keeping heating on most days for it to work - would it work even when rads aren't heating up?

Thanks again for your help.

 

[Goldspoon]

Is the pump actually working? Upstairs rads might be just heating via gravity.

 

[D_Hailsham]

Was the system OK before you added the three extra rads? If so the boiler may need to be adjusted to give a higher output - the 10/16 can be adjusted to give between 10kW and 16kW. Time how long it takes for the right hand dial on the gas meter to make one rotation with the boiler running flat out. Then post the result and what type of meter you have (metric or cubic ft) and we can work out the output of your boiler.

The system probably needs balancing.

Remove the Westherm head by setting the valve to max and then undoing the knurled screw below the plastic head (Turn anticlockwise when looking at the top of the valve). It may need a bit of effort or grips if the head has been on for a long time.

 

[D_Hailsham]

His possible theory is that the pump we have at the moment senses when the valves "think" they are at the right temperature and it shuts down.

Nice theory, but it does not work like that. The pump will be controlled either by the boiler directly or via the room thermostat.

I assume you do have a room thermostat?
If so where is it located?
Is there a TRV on the rad near the thermostat?

 

[karenmac]

Hi

Looking at the meter going round was scary - I was seeing £ signs. It did a full rotation on about 20 - 25 seconds - Have I done that right?? Its metric

There is a room thermostat on the middle floor in the hall the radiator there doesn't have a thermostatic valve, neither does the one in the lower hall.

We didn't add the three radiators. I think they were added gradually as rooms were changed or added.

karenmac

 

[D_Hailsham]

It did a full rotation on about 20 - 25 seconds - Have I done that right?? Its metric

Then the boiler is probably set to max output.

There is a room thermostat on the middle floor in the hall the radiator there doesn't have a thermostatic valve, neither does the one in the lower hall.

You said it was a town house. Presumably all you have on the ground floor is a garage and entrance hall - and possibly a store/utility room.

The heat from the ground floor radiator is rising up the stair well and affecting the wall thermostat - turning it off too early. Fit a thermostatic valve on the ground floor rad and set it to 3 or thereabouts. The rad will then close down before it affects the wall stat (you don't need the hall at 21°C).

We didn't add the three radiators. I think they were added gradually as rooms were changed or added.

Understood.

15.45 metres of rads is roughly 15.45kW, so the boiler should be OK - though, in theory, you should take into account the heat lost in all the pipework, which can add up to several kW.

I still reckon the system needs balancing.

 

[bengasman]

Cleaner does not work where it does not go; cold rads will therefore not be cleaned.
2 Solutions:
Turn all the warm rads off, and see which cold ones warm up, or run the rads one by one.
Balance the system first, description in FAQ