Back boiler Powerflush

[verdigrey]

Hi Guys ,
Would welcome some advice with this one please .
Situation , 3 bed semi with Parkray inset fire with back boiler , does Cylinder and 11 rads . In rented house , Landlord says it used to heat everything up fine ( a few years ago ) . Been empty for a while , New tennants say it heats cyl ok , but when pump goes on it heats rads only warm , not hot .
I hired a powerflush and used X800 . Water a bit grey , but not really bad . I was only able to use it with cold water as I had plugged F & E and I didnt want to light the fire .
Any way , After finishing job , Tennants lit fire , 3 - 4 hours later cyl getting hot , but when pump went on rads not much better . I said keep trying and i will ring them next week . I suspect the back boiler is coated with rust or scale and X800 didnt clear it . Any ideas what to do next please ?

 

[Roger Welton]

How did you connect and did you put a means of shutting off (gravity?) hot water loop. Failing that is the pump ok

 

[SimonG]

Are you in a hard water area?

 

[verdigrey]

Hi Roger and Simon , Thanks for your replies ,
I connected at the pump valves , No I did not shut off the gravity loop , But before I pluged the feed pipe I drained some water out of the feed tank thru the gravity loop and thru the back boiler and out of a pump valve . The water drained quite quickly ( 22mm ) . The pump is fairly new . Yes we are in a hard water area .

 

[tamz]

I doesn't need a powerflush and the only thing wrong with the boiler is it needs a bigger fire on and the right coal. A Parkray roomheater has an optimal output of 40,000btu burning the right fuel. Normally it will be putting out around 20,000.
Nobody knows how solid fuel works anymore.

 

[lame plumber]

I doesn't need a powerflush and the only thing wrong with the boiler is it needs a bigger fire on and the right coal. A Parkray roomheater has an optimal output of 40,000btu burning the right fuel. Normally it will be putting out around 20,000.
Nobody knows how solid fuel works anymore.

you can tell he sucks wurthers originals

 

[verdigrey]

Thanks for your comments Tamz . All I can say is the Tennants said that they ARE used to useing a back boiler in their previous house and it heated the house ok .
At the moment they are useing Anthracite , which from memory has a very high calorific value so it aught to heat the rads ok .

 

[peteheat]

The fuel is spot on for a Parkray, anytime I had issues with back boilers or stoves with back boilers the problem was the customer not the boiler;

Not cleaning the boiler / baffles as often as they should.

Not running on the correct air input, anthracite can stay alight for hours giving a lovely glow in a Parkray, sadly that is not sufficient for replacing the heat in the boiler, more air = more fuel = more heat.

Terrible having to ask customers trick questions but you might try this, is the temperature in the radiators about the same all the time? if Yes then more fuel and air is needed.

You may have to put a load of fuel on the fire yourself to show how this works, if the customer was using an open fire back boiler they didn't control the air supply, the Parkray gives that control which could be the problem.

 

[REDSAW]

the parkray is designed to burn antracite.
i think pumps weak?

 

[tamz]

11 rads on a room heater is oversized for the heat it can produce unless they are very small radiators. It is like pyshing in the wind. Unless they are constantly feeding it with the damper open and the thermostat to maximum it won't heat the rads well at all. Rads on solid fuel heating are more of a background heat. The rads can't really be sized to the rooms.
It is defiantly a boiler problem (not sludge as you could drive a bus through the insides). Check the damper is clear with no restrictions, check the thermostat is set correctly and opens and closes as it should, check the draw and check the door seals.

 

[tamz]

I've never fitted a roomheater where i had tho set the pump higher than 1. Even then sometimes i've had to check the valves back. It doesn't take much pumping.

 

[verdigrey]

Morning Guys ,
Thanks for your usefull comments Peteheat , Tamz and Redsaw .
I like the idea of asking the customer trick questions so we get to the truth of what is really happening . I will be back there mid next week so will check the Parkray over then . Cheers .