Causal loop diagram:

House temperature $-->-$ Heat loss to environment

Heat loss to environment $-->-$ Furnace on time

Furnace on time $-->-$ Heat gain from furnace

Heat gain from furnace $-->+$ House temperature

Outside temperature $-->+$ Heat loss to environment

Flow and stock diagram:

Stocks:

House temperature $(H)$

Flows :

Heat loss to environment $($L$)$

Heat gain from furnace $($G$)$

Equations:

$d\frac{H}{dt}=-L+G$

$L=k(H-Te)$

$G=F{t}_{o}n$

k: heat transfer coefficient

Te: outside temperature

$F$ : furnace heating capacity

t$\_$on: furnace on time

$!$Show the diagrams by drawing them on paper please