Central Heating Struggling in the Cold

[DIYDisaster987]

Looks like these two are sold together as a frost protection kit. I think these were added years ago when the boiler was moved outside into the garage.

Seems to have been doing it's job lately!

 

[DIYDisaster987]

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[fourtytwo]

In the house I moved to recently also with a boiler in the garage and 11 rads the pipe run is very long with many 90 degree elbows so the pump is barely able to drive the water around even after much balancing. If the hot water is on at the same time the radiators barely get warm even with the HW gate valve only open 1/2 turn. My solution is the programmer, when the boiler 1st starts the system is on HW+CH but after 1/2 hr switches to CH only. Times would vary according to your HW demand. I also have the frost stat rigged to only run the HW to save gas.

I would never buy a house with any kind of external boiler again, complete waste of gas and poor heating system result!

 

[MeldrewsMate]

My Boiler Temp is already at Maximum (now 5 out of 5).
The original Temp 3 out of 5 was set by my plumber.

This is new information, and conflicts with your very precise statement earlier that 'the flow temperature is 59C'. The boiler 'stat at maximum should give a flow temperature of about 80C on an old thumper like the Flamingo.
You have been given advice to flush the system, clean out the header tank, add cleaning chemicals, and add a magnetic filter. This is good advice.
Be very careful to avoid placing any valve in the open vent route between the boiler and the vent over the header tank.
I have found that the plug method of airlocking is almost universally unsuccessful on anything but 15mm and smaller pipework; besides, you'll be draining the system once the cleaner has done its work, so do the weeping valves and magnetic filter on an empty system.

 

[DIYDisaster987]

This is new information, and conflicts with your very precise statement earlier that 'the flow temperature is 59C'. The boiler 'stat at maximum should give a flow temperature of about 80C on an old thumper like the Flamingo.
You have been given advice to flush the system, clean out the header tank, add cleaning chemicals, and add a magnetic filter. This is good advice.
Be very careful to avoid placing any valve in the open vent route between the boiler and the vent over the header tank.
I have found that the plug method of airlocking is almost universally unsuccessful on anything but 15mm and smaller pipework; besides, you'll be draining the system once the cleaner has done its work, so do the weeping valves and magnetic filter on an empty system.

Apologies for the late reply, I didn't receive a notification for some reason.

I think my method for measuring the temperature could be flawed tbh. apologies if it mislead or confused.

 

[DIYDisaster987]

I have added a Magnaclean Pro 2 on the final return to the boiler and added X400 and sorted a few leaky lockshields/TRVs. Was collecting sludge after checking after one hour of running! Have checked a couple of times since and loads being collected.
Greate advice, thanks for that JohnD and thanks to all others that responded. Heating already much improved, think the old Flamingo may live to see another day.

Just as a final thought, does anyone have a rough idea of how much more efficient a new boiler could be compared to the old Flamingo? Given my gas costs will be over £2.5k this year it may be economical to change it anyhow.

 

[JohnD]

I used to have a Flamingo and when I changed to a Vitodens I think the gas usage, averaged over a few years, dropped by about 20%. But I would have to find my old records to check.

BTW after it was removed I looked inside the heat exchanger and there was lots of scale that could never have drained out.

Once you have dealt with your sludge, add X200 with the final refill with the X100.

X200 slowly dissolves old limescale (you do not drain it out)

 

[AdrianUK]

Looks like these two are sold together as a frost protection kit. I think these were added years ago when the boiler was moved outside into the garage.

Seems to have been doing it's job lately!


View attachment 289227View attachment 289228
View attachment 289229

Fairly standard setup.

The frost stat fires up the system when the temperature it is exposed to falls below about 5 deg C. However, since that space is unheated, running the boiler will never warm the space up so the frost stat wont be satisfied until the spring! The answer is to fit a pipe stat to the boiler return.... once the boiler has got the system water warm, the pipe stat opens & shuts things down again.

 

[DIYDisaster987]

The X400 and the Magnaclean have been doing their job and I've cleaned it out each week and its had a fair bit of sludge sticking to the magnets.
The heating is much much better but its decision time now! I need to drain it down to remove the X400 but I've been quoted ~£700 for a Powerflush (which would save me a job!).
Part of me thinks its not worth it now. My main concern is I have it done and old Flamingo is on its last legs and I have to replace it and then need another Powerflush for new boilder warranty. Also comments on here about it finding leaks on older systems put me off.
In terms of efficiency of system as it is, all the radiators get hot but it takes a long time to get the thermostat to switch off at 18 degrees on very cold days.

 

[JohnD]

Draining and rinsing will remove most of the remaining particles, including non-magnetic ones that the Magnaclean did not trap. It will also disturb some more of the sludge so the Magnaclean can trap it from the circulating water.

Are you aware of a problem that a powerflush will fix? If not, keep your money until you need a new boiler.

Summer is the best time to change a boiler.

 

[DIYDisaster987]

Draining and rinsing will remove most of the remaining particles, including non-magnetic ones that the Magnaclean did not trap. It will also disturb some more of the sludge so the Magnaclean can trap it from the circulating water.

Are you aware of a problem that a powerflush will fix? If not, keep your money until you need a new boiler.

Summer is the best time to change a boiler.

By rinsing do you mean leaving bottom drain valve open and header tank filling? Would you run the CH pump for this?

I'm surprised no one makes some kind of adapter for the Magnaclean to allow you to push mains pressure water around the system to flush it. A 'DIY flush'!

Also wanted to ask what is the best way to get the 3 way switch into the mid position. When I turn off the controller it always moves to CH or Water (cant remember which). Tried to estimate the mid position with the motor removed but hard to do with such a small movement. Think this was why it took so long to drain down last time!

 

[JohnD]

By rinsing do you mean leaving bottom drain valve open and header tank filling? Would you run the CH pump for this?

No, that would give very weak flow. I mean emptying, refilling, running the pump to circulate it, then draining again.

Since sediment falls to the bottom of radiators, IMO it is not necessary to bleed radiators to fill them to the top for intermediate rinse, only the first and last to wash chemicals out. Opinions may differ on that, but it saves time.

In my house, the radiator valves fit a garden hose, or washing machine connector, so I can do a mains flush, but it will take the shortest route unless you close all the radiators and open them one at a time.

You can also fit a full-bore drain cock, which a hose fits. Gushing the water out is better for rinsing out dirt.

You should be able to push the lever with your finger to the manual position.

 

[DIYDisaster987]

Thats great, thanks once again John for you help.

 

[Johntheo5]

By rinsing do you mean leaving bottom drain valve open and header tank filling? Would you run the CH pump for this?

I'm surprised no one makes some kind of adapter for the Magnaclean to allow you to push mains pressure water around the system to flush it. A 'DIY flush'!

Also wanted to ask what is the best way to get the 3 way switch into the mid position. When I turn off the controller it always moves to CH or Water (cant remember which). Tried to estimate the mid position with the motor removed but hard to do with such a small movement. Think this was why it took so long to drain down last time!

With the controller switched off and if no power to the MP valve it will allways move to the DHW position, with power on, if the valve is in mid position and the DHW was called in last and then the CH & DHW demands both cease then the valve will move to the DHW position (lasyt port of call), if the CH was called for last then the valve will move to the CH position when demands stop.

You should I think be able (with all power off ) to manually move the valve to mid position, not sure about rads only.

 

[DIYDisaster987]

System was flushed and refilled and is now working really well with all radiators too hot to touch (after a little balancing) so power flush not needed!

One thing thats worth mentioning for anyone reading this with similar sludge issues was that each time I've drained the system down it flows out quite happily then slows to a dribble for hours, I'm assuming because of the sludge. As most of my downstairs rads have drain cocks I conected a shorter length of hose and then connected my wet vac to it, just by using my hand to connect the two. You could see that it was the sludge it was getting out because it got darker each time I emptied it, plus it saved hours.